Patent Grant
11293371
The present invention relates to a control device for a fuel injection valve which injects and supplies fuel to an internal combustion engine.
Due to the recent tightening of automobile fuel consumption and exhaust regulations, it is required to simultaneously achieve low fuel consumption and high output of internal combustion engines and to be suitable for a wide operating range of internal combustion engines. As one of means for achieving this, it is required to expand a dynamic range of a fuel injection valve. In order to expand the dynamic range of the fuel injection valve, it is necessary to improve dynamic flow characteristics while ensuring conventional static flow characteristics. As a method for improving these dynamic flow characteristics, it is known to reduce a minimum injection amount through half lift control.
The half lift control controls a fuel injection valve with high accuracy in a state (hereinafter referred to as a half lift region) before a valve body provided in the fuel injection valve reaches a fully valve opening position (hereafter referred to as full lift). It is known that a variation in the injection amount in the half lift region becomes large due to the individual difference of the fuel injection valve. Therefore, various techniques for detecting the individual difference occurring in each fuel injection valve have been proposed.
PTL 1 below discloses a technique for indirectly detecting individual difference in a valve opening operation of a fuel injection valve (specifically, when a valve body is in a valve opening state) based on electrical characteristics. It is also a known technique to detect a closing operation of a fuel injection valve from electrical characteristics.
PTL 1: JP 2014-152697 A
In the half lift region, the fuel injection amount has a strong correlation with the actual valve opening time. Therefore, it is possible to know the variation in the injection amount by knowing the difference between the valve opening start timing and the valve closing completion timing (that is, the actual valve opening time) for each injection valve. Since the fuel injection valve having a preliminary stroke mechanism keeps a valve opening force constant in a region in which the injection amount is relatively large in the half lift region, the valve opening start timing is also constant. Therefore, the variation in the injection amount can be detected by detecting the valve closing completion timing. On the other hand, in the extremely small injection region, the valve opening force is not constant, and the valve opening start timing tends to be delayed as a pulse width is shortened. Therefore, in order to control the variation in the injection amount in the extremely small injection region, it is also necessary to detect the valve opening start timing. However, in this region, since the amount of energization is small and the energization time is extremely short, it is difficult to detect the valve opening start timing based on the electrical characteristics.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a technique for identifying a variation in an injection amount by estimating a valve opening start timing in an extremely small injection region of a half lift region.
A fuel injection control device according to the present invention estimates a valve opening start timing of a fuel injection valve by referring to a characteristic of a reference fuel injection valve acquired in advance.
According to the present invention, a fuel injection control device can acquire a valve opening start timing of a fuel injection valve even in an extremely small injection region. Therefore, it is possible to reduce the variation in the injection amount of the fuel injection valve, and it is possible to prevent unintended torque variation or deterioration of fuel consumption and exhaust performance by expanding a control range in which the extremely small injection is performed.
The engine condition detection unit 111 acquires various pieces of information such as an engine speed, an intake air amount, a cooling water temperature, a fuel pressure, and an engine failure state. The pulse signal calculation unit 112 calculates an injection pulse (width) which defines the fuel injection period of the fuel injection valve 200 based on the various pieces of information acquired from the engine condition detection unit 111.
The waveform command unit 113 calculates a command value of a driving current for opening the fuel injection valve 200 or maintaining the valve opening state, and outputs the command value to the driving IC 120.
The high voltage generation unit 130 uses a battery voltage 301 supplied through a fuse 302 and a relay 303 to generate a high power supply voltage (hereinafter referred to as a high voltage) required when the electromagnetic solenoid type fuel injection valve 200 is opened. In addition, the high voltage generation unit 130 boosts the battery voltage 301 to reach a desired target high voltage, based on a command from the driving IC 120.
Therefore, as a power source for the fuel injection valve 200, power supplies of two systems, that is the high voltage for securing a valve opening force of a valve body and the battery voltage 301 for holding the valve opening such that the valve body is not closed after the valve is opened can be supplied.
The two switches 141 and 142 are provided on the upstream side and the downstream side of the fuel injection valve 200. When these switches are turned on, the driving current is supplied to the fuel injection valve 200. The driving IC 120 controls the high voltage or the battery voltage 301 applied to the fuel injection valve 200 by switching the switches based on the injection pulse (width) calculated by the pulse signal calculation unit 112 and the driving current profile calculated by the waveform command unit 113. Therefore, the driving current supplied to the fuel injection valve 200 is controlled.
When the valve closing timing detection unit 150 controls the fuel injection valve 200 in the half lift region, the valve closing timing detection unit 150 detects the valve closing timing from the characteristic change of the driving voltage applied to the injection valve as a means for detecting the individual difference in injection valve behavior for each injection valve. The detection result is transmitted to the pulse signal calculation unit 112.
In the section 202, the valve body vibrates at the valve opening end in the injection valve due to an excess valve opening force, and the injection amount and the pulse width are not simply proportional to each other. Therefore, for example, the region in which the pulse width and the injection amount are proportional to each other can be expanded by adjusting the valve opening force with the driving current waveform different from that of the section 203 and reducing the vibration at the valve opening end.
The section 201 is a region in which the valve behavior and the injection amount have a strong correlation. In this region, since the mechanical characteristic or the electrical characteristic of the injection valve strongly affect the valve behavior, the pulse width and the injection amount are not simply proportional to each other, and the variation in the injection amount is simply aligned due to the variation in each injection valve.
Therefore, in the conventional art, the valve opening force is adjusted by switching the driving current, and the pulse width is controlled for each injection valve based on the detection result of the valve behavior, thereby reducing the individual difference in the injection amount. In the conventional art, attempts have been made such that the region in which the pulse width and the injection amount are proportional to each other expands to the section 201. However, it is difficult to control the variation in the injection amount for each injection valve even in the conventional art, especially in the extremely small injection amount region of the section 201. The present invention follows the conventional art, and further aims to accurately control the variation in the injection amount for each injection valve even in this extremely small injection region.
The injection valve starts opening at T302, and at T303, the valve body reaches the valve opening end and becomes the full lift. During a period from T303 to T304, the valve body vibrates and behaves unstable due to the excessive valve opening force. After the injection pulse is cut off at T305 and the energization is stopped, the valve opening force is lost, the valve body moves to the valve closing position, and the valve is closed at T306. In the full lift region, the valve body is fully opened, and therefore the relationship between the pulse width and the injection amount is simply proportional.
The driving current starts energizing according to a preset current waveform profile. A high-voltage current is energized to a coil of the fuel injection valve 200, and the energization is cut off when the energization time (time from T401 to T403) elapses or when the driving current reaches 412a.
After the energization is cut off, the current quickly becomes 0 A. While energized, a magnetic force is generated by the coil, and a mover and a valve body provided in the fuel injection valve 200 receive, as the valve opening force, the difference between the magnetic force applied to the mover and the valve body and the force in the valve closing direction.
When the mover starts moving from P401 at which the valve opening force becomes a positive value in the valve opening direction, moves by a preliminary stroke 451 which is a length at which the mover can operate, and then comes into contact with the valve body at T411. The valve body starts opening at T411 due to the impact force due to the contact with the mover. Therefore, T411 will be referred to as the valve opening start timing.
Since the energization is completed at T411, it is not affected by the magnetic force, but is affected by spring load and fuel pressure in the valve closing direction. Since the spring load and the fuel pressure in the valve closing direction can be regarded as constant in a short period, the valve body makes a constant acceleration parabolic motion. A relationship between the time and the position of the valve body in the fuel injection valve 200 is represented by a parabola 422. The valve body completes the valve closing at T422 and the injection stops.
The mover continues to operate to a mover reference position and moves to P403.
Since the fuel injection amount is the amount of fuel injected while the valve body is in a parabolic motion, it can be seen that there is a strong correlation between the injection amount and the valve behavior. Since the amount of the valve behavior correlates with an area 431 surrounded by the parabola 422, it can be said that the injection amount also has a strong correlation with the area 431. Therefore, if the area 431 can be known, the injection amount can be known, but it is not practical to measure the valve behavior during the injection valve operation. When focusing on the fact that the valve behavior is a constant acceleration parabolic motion, it is mathematically obvious that the area 431 correlates with the time from the valve opening start timing T411 to the valve opening completion timing T422, that is, the valve opening time length 441. Therefore, if the valve opening time length 441 is detected, the injection amount can be obtained.
In the region in which the injection amount is controlled by the pulse width (that is, the region which is controlled by the injection pulse width longer than that from T401 to T403.), the valve behavior becomes a parabola 423. In addition, since the valve opening force is sufficient in this region and the impact force when the mover comes into contact with the valve body is constant, the valve opening start timing T411 is at the same position. Therefore, in the conventional art, the valve opening time length is obtained by detecting the valve closing time, and the injection amount control is performed based on the valve opening time length.
On the other hand, what the present invention controls is a region which is controlled with the pulse width shorter than that from T401 to T403. In this region, a driving current waveform is 411, and a maximum current 411a is smaller than that of 412a. Therefore, the magnetic force is reduced and the valve opening force is weakened, which affects the responsiveness of the mover. That is, the time when the mover comes into contact with the valve body is delayed by a time length 443. Since the assumption that the valve opening start timing is constant as in the conventional art is not established, it is necessary to know a valve opening start timing T412 in order to detect a valve opening time length 442. Although a technique for detecting the valve opening completion timing from the change in the current value is known, it is difficult to apply the technique because the valve opening starts after the energization is completed in the region targeted by the present invention.
The upper drawing of
The pulse width of the injection valve 501 needs to be corrected to T501. Therefore, according to the conventional art, the valve closing timing of each injection valve can be detected and the pulse width of the injection valve 501 can be corrected to, for example, T502. This correction in the conventional art assumes that the valve opening start timing is constant. However, as described above with reference to
In the lower drawing of
As described above with reference to
The mechanical characteristic relates to the difficulty of the movement of the mover 603. For example, there are the mass of the mover 603, the spring load by the mover position defining spring 604, the design value of the gap 608, and the preliminary stroke 609 related to the operating time of the mover 603. Various other factors can be considered, but the above factors have a particularly great influence.
The electrical characteristic includes a driving voltage (effective voltage value or target value) which affects the strength of the driving current that generates the valve opening force, a coil resistance which makes it difficult to energize the driving current, a coil inductance, and the like. Various other factors can be considered, but the above factors have a particularly great influence.
The upper drawing of
Therefore, since the movement of the mover is accelerated in proportion to the rise in the driving voltage, the valve opening start timing is shortened.
The middle drawing of
The lower drawing of
Assuming that the relationship between each parameter illustrated in
For example, in the upper drawing of
As shown in the upper drawing of
The reference data storage unit 114 stores reference data. The reference data describes the relationship between the valve opening start timing of the reference fuel injection valve and the pulse width or the injection amount, and also describes the relationship between each parameter illustrated in
In the conventional art, the fuel injection amount is controlled in a region in which the valve opening start timing can be regarded as constant. Therefore, an actual valve opening time length calculation unit 1125 calculates an actual valve opening time length from a difference between a predetermined valve opening start timing and a valve closing timing detected by a valve closing timing detection unit 150. The pulse width calculation unit 1126 calculates a pulse width correction amount by comparing a calculation result of a target valve opening time length calculation unit 1124 with the actual valve opening time length. Furthermore, an injection pulse width is corrected by the pulse width correction amount, based on a engine condition acquired from an engine condition detection unit 111, and the corrected injection pulse width is output as the injection pulse width.
On the other hand, in the first embodiment, the valve opening start timing of the reference fuel injection valve is obtained according to the description of the reference data, and the individual difference between the valve opening start timing of the reference fuel injection valve and the valve opening start timing of the fuel injection valve 200 is obtained according to the description of the individual data 210. A target valve opening start timing calculation unit 1123 obtains the valve opening start timing of the fuel injection valve 200 based on these. Details of the respective functional units will be described with reference to
The valve opening start timing selection unit 11252 acquires the required injection pulse width or the required injection amount (S1601). The valve opening start timing selection unit 11252 acquires the valve opening start timing of the fuel injection valve 200 from the target valve opening start timing calculation unit 1123 (S1602). The valve opening start timing selection unit 11252 determines whether or not the required injection amount or the required pulse width acquired in S1601 is smaller than a predetermined value (S1603). When the required value is smaller, the value obtained from the target valve opening start timing calculation unit 1123 is adopted (S1604); otherwise, the fixed valve opening start timing 11251 is adopted (S1605).
The predetermined value in step S1603 may be either a required value corresponding to the boundary between the full lift region and the half lift region, or a minimum required value which is less than or equal to the required value and at which the valve opening force is sufficiently large and the valve opening start timing is constant. As shown in
Similar to the predetermined value in step S1603, the predetermined value in step S1804 may be either a required value corresponding to the boundary between the full lift region and the half lift region, or a minimum pulse width which is less than or equal to the required value and at which the valve opening force is sufficiently large and the valve opening start timing is constant.
The fuel injection control device 100 according to the first embodiment is the fuel injection control device (100) which controls the fuel injection valve (200) of the internal combustion engine, and includes the valve opening start timing calculation unit (1123) which estimates the valve opening start timing at which the fuel injection valve (200) starts to open, and the reference data storage unit (114) which stores the reference data describing the characteristic of the reference fuel injection valve used as the reference when the valve opening start timing calculation unit (1123) estimates the valve opening start timing. The valve opening start timing calculation unit (1123) estimates the valve opening start timing by referring to the reference data using the characteristic parameters representing the characteristic of the fuel injection valve (200). Therefore, the valve opening start timing of the fuel injection valve 200 can be estimated from the characteristic of the reference fuel injection valve.
The reference data describes the relationship between the reference characteristic parameter representing the characteristic of the reference fuel injection valve and the reference valve opening start timing at which the reference fuel injection valve starts to open. The valve opening start timing calculation unit (1123) estimates the valve opening start timing by acquiring, from the reference data, the reference valve opening start timing corresponding to the characteristic parameter representing the characteristic of the fuel injection valve (200). Therefore, the valve opening start timing of the fuel injection valve 200 can be estimated by grasping the relationship between the characteristic of the reference fuel injection valve and the reference valve opening start timing in advance.
The fuel injection control device (100) further includes the reference valve opening start timing calculation unit (1121) which obtains the reference valve opening start timing using the reference data.
The fuel injection control device (100) further includes the individual difference calculation unit (1122) which obtains the difference between the reference valve opening start timing and the valve opening start timing using the characteristic of the fuel injection valve (200). The valve opening start timing calculation unit (1123) estimates the timing, at which the fuel injection valve (200) starts to open, according to the difference obtained by the individual difference calculation unit (1122). Therefore, even when it is difficult to detect the valve opening start timing itself of the fuel injection valve (200), the valve opening start timing can be estimated from the difference from the reference valve opening start timing.
The reference data describes the relationship between the reference characteristic parameter and the reference valve opening start timing for each of the plurality of reference characteristic parameters. The valve opening start timing calculation unit (1123) identifies the reference characteristic parameter corresponding to the characteristic parameter and acquires, from the reference data, the difference between the valve opening start timing and the reference valve opening start timing corresponding to the identified reference characteristic parameter. The valve opening start timing calculation unit (1123) estimates the valve opening start timing by multiplying the difference by the weight determined for each reference characteristic parameter and adding the multiplying result to the reference valve opening start timing. Therefore, even when the influence on the valve opening start timing differs according to the characteristic of the fuel injection valve (200), the valve opening start timing can be estimated in consideration of the influence.
The fuel injection control device (100) further includes the valve opening time length calculation unit (112) which defines the valve opening time length for opening the fuel injection valve (200). The valve opening time length calculation unit (112) defines the valve opening time length so as to open the fuel injection valve (200) from the valve opening start timing estimated by the valve opening start timing calculation unit (1123) until the target valve opening time length of the fuel injection valve (200) is reached. Therefore, the injection amount by the fuel injection valve (200) can be adjusted to the target value according to the estimated valve opening start timing.
The fuel injection control device (100) further includes the switching elements (141, 142) which turn on/off the driving current supplied to the fuel injection valve (200). The fuel injection control device (100) further includes the pulse width calculation unit (1126) which calculates the pulse width of the signal for turning on the switching elements (141, 142). The pulse width calculation unit (1126) calculates the pulse width so as to open the fuel injection valve (200) from the valve opening start timing estimated by the valve opening start timing calculation unit (1123) until the target valve opening time length of the fuel injection valve (200) is reached. Therefore, the injection amount by the fuel injection valve (200) can be adjusted to the target value using the pulse width control according to the estimated valve opening start timing.
The fuel injection control device (100) further includes the valve closing timing detection unit (150) which detects the valve closing timing when the fuel injection valve (200) is closed. The fuel injection control device (100) further includes the actual valve opening time length calculation unit (1125) which calculates the actual valve opening time length, at which the fuel injection valve (200) is actually opened, according to the valve opening start timing and the valve closing timing. The valve opening time length calculation unit (112) adjusts the valve opening time length so that the actual valve opening time length matches the target valve opening time length. Therefore, the valve opening time length can be adjusted according to the estimated valve opening start timing and the actual valve closing timing. That is, the injection amount of the fuel injection valve 200 can be controlled by utilizing the technique for detecting the valve closing timing in the conventional art.
The reference data describes the mechanical characteristic of the reference fuel injection valve. The mechanical characteristic of the reference fuel injection valve is at least one of the stroke amount (609) in which the mover (603) included in the reference fuel injection valve moves from the time when the mover (603) starts to move to the time when the reference fuel injection valve comes into contact with the valve body (605), the mass of the mover (603), the gap (608) provided between the mover (603) and the reference fuel injection valve in the portion in which the mover (603) slides, and the spring load of the spring (604) which moves the mover (603) in the direction of closing the reference fuel injection valve. Therefore, the valve opening start timing can be estimated according to the movement characteristic of the mover (603). Since the movement characteristic of the mover (603) can be known at the time of design or manufacture, it is useful to use this for estimation.
The reference data describes the electrical characteristic of the reference fuel injection valve. The electrical characteristic of the reference fuel injection valve is at least one of the electrical resistance of the coil (602) which electromagnetically drives the valve body of the reference fuel injection valve, the inductance of the coil (602), and the effective value or the target value of the driving voltage supplied to the reference fuel injection valve. Therefore, the valve opening start timing can be estimated according to the electrical characteristic of the fuel injection valve (200). Since the electrical characteristic of the fuel injection valve (200) can be obtained relatively easily, it is useful to use this for estimation.
The fuel injection control device (100) further includes the driving circuit (120) which opens the fuel injection valve (200) by supplying the driving current thereto. The driving circuit (120) lowers the driving current when the fuel injection amount by the fuel injection valve (200) reaches the target value. Therefore, the injection amount by the fuel injection valve (200) can be appropriately controlled on the assumption of the estimated valve opening start timing.
The fuel injection control device (100) further includes the actual valve opening time length calculation unit (1125) which obtains the actual opening time length when the fuel injection valve (200) is opened. The actual valve opening time length calculation unit (1125) switches whether or not to obtain the actual valve opening time length using the valve opening start timing estimated by the valve opening start timing calculation unit (1123) according to at least one of the first required value for the injection amount of fuel injected by the fuel injection valve (200) or the second required value for the pulse width of the driving signal for controlling the switching elements (141, 142) supplying the driving current to the fuel injection valve (200). When the first required value or the second required value is greater than or equal to a predetermined threshold value, the actual valve opening time length calculation unit (1125) uses a predefined timing as the valve opening start timing of the fuel injection valve (200) instead of the valve opening start timing estimated by the valve opening start timing calculation unit (1123) (S1605). When the first required value or the second required value is less than the predetermined threshold value, the actual valve opening time length calculation unit (1125) uses the valve opening start timing estimated by the valve opening start timing calculation unit (1123) as the valve opening start timing of the fuel injection valve (200) (S1604). The predetermined threshold value is set to be less than or equal to the value for fully opening the fuel injection valve (200). Therefore, the fuel injection valve (200) can be controlled by following the conventional control procedure in the full lift region and using the result of estimating the valve opening start timing according to the first embodiment in the half lift region.
The fuel injection control device (100) further includes the pulse width calculation unit (1126) which obtains the pulse width of the driving signal for controlling the switching elements (141, 142) supplying the driving current to the fuel injection valve (200). The pulse width calculation unit (1126) obtains the normal value of the pulse width according to at least one of the first required value, the second required value, and the fuel pressure of the fuel injection valve (200) (S1802). When the normal value is greater than or equal to a predetermined threshold value, the pulse width calculation unit (1126) uses the normal value as the pulse width of the driving signal (S1807). When the normal value is less than the predetermined threshold value, the pulse width calculation unit (1126) corrects the normal value using the difference between the actual valve opening time length and the target valve opening time length and uses the corrected value as the pulse width of the driving signal (S1806). Therefore, the fuel injection valve (200) can be controlled by following the conventional control procedure in the full lift region and using the result of estimating the valve opening start timing according to the first embodiment in the half lift region.
In the first embodiment, it has been described that the valve opening time length is controlled by controlling the driving pulse width for driving the switches 141 and 142. On the other hand, the pulse signal calculation unit 112 controls the pulse width in order to control the valve opening time length, and the waveform command unit 113 controls the peak value of the driving current or the like (302a to 302c in
The fuel injection amount correlates with the valve behavior. Specifically, the target injection amount is achieved when a time integral S of the target injection valve behavior 831 and a time integral S′ of the actual injection valve behavior 832a in
A value obtained by converting the target valve opening time length into the current integral value is set as a target valve opening current integral value, and a value obtained by converting the actual valve opening time length into the current integral value is set as an actual valve opening current integral value. The waveform command unit 113 calculates the difference between the target valve opening current integral value and the actual valve opening current integral value. The waveform command unit 113 calculates a target current integral value of the fuel injection valve 200 based on this difference. The waveform command unit 113 calculates the current integral value by detecting the driving current during injection, for example, every 1 ms, and compares the current integral value with the target current integral value. The waveform command unit 113 cuts off the driving current when both match each other. A specific method for cutting off the driving current includes, for example, (a) lowering the current waveform (the peak value of the driving current), (b) lowering the driving pulse, (c) directly inputting the energization stop command to the driving IC 120.
When obtaining the above integral, the waveform command unit 113 does not necessarily have to strictly time-integrate the current waveform, and may obtain an approximate integral value. For example, the integral value of the driving current may be obtained by the approximate calculation using the peak value of the driving current and the timing at which the driving current or the driving pulse starts to fall. For example, the current waveform of
In the first embodiment, it has been described that the driving pulse is controlled in order to align the fuel injection amount with the target value, but the driving current waveform may be controlled instead of or in combination with this. Specifically, the waveform command unit 113 may obtain the time integral of the driving current and control the driving current waveform so that the time integral approaches the target value.
The fuel injection control device (100) further includes the waveform command unit (113) which designates the current waveform of the driving current supplied to the fuel injection valve (200). The waveform command unit (113) designates the current waveform of the driving current so as to open the fuel injection valve (200) from the valve opening start timing estimated by the valve opening start timing calculation unit (1123) until the target valve opening time length of the fuel injection valve (200) is reached. Therefore, the injection amount of the fuel injection valve (200) can be controlled to the target value by controlling the driving current waveform in addition to or instead of the driving pulse width.
The waveform command unit (113) increases or decreases the time integral of the driving current to open the fuel injection valve (200) from the valve opening start timing estimated by the valve opening start timing calculation unit (1123) until the target valve opening time length of the fuel injection valve (200) is reached. Therefore, the injection amount of the fuel injection valve (200) can be controlled to the target value independently of the control of the driving pulse width.
The waveform command unit (113) increases or decreases the time integral of the driving current by changing at least one of the peak current value of the driving current or the timing at which the driving current starts to fall. Therefore, the time integral of the driving current can be easily obtained.
The present invention is not limited to the above-described embodiments and various modifications can be made thereto. For example, the embodiments have been described in detail for easy understanding of the present invention and are not intended to limit to those necessarily including all the above-described configurations. In addition, a part of a configuration of a certain embodiment can be replaced with a configuration of another embodiment, and a configuration of another embodiment can be added to a configuration of a certain embodiment. Furthermore, it is possible to add, remove, or replace another configuration with respect to a part of a configuration of each embodiment.
In the above-described embodiments, it has been described that the difference between the valve opening start timing of the reference fuel injection valve and the valve opening start timing of the fuel injection valve 200 is obtained, but ratios of the two timings may be used instead of the difference. Similarly, in the second embodiment, these ratios may be used instead of the difference between the target valve opening current integral value and the actual valve opening current integral value.
All or part of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware, for example, design of integrated circuits or the like. In addition, each of the above-described configurations, functions, and the like may be realized by software which causes a processor to interpret and execute a program that realizes each function. Information of the programs, tables, files, and the like that realize each function can be stored in a memory device such as memory, hard disk, solid state drive (SSD), or a recording medium such as IC card or SD card. Furthermore, control lines or information lines indicate what is considered to be necessary for the description, and all the control lines or information lines are not necessarily shown on products. In practice, it can be considered that almost all the structures are mutually connected.
| Number | Date | Country | Kind |
|---|---|---|---|
| JP2018-137156 | Jul 2018 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2019/026563 | 7/4/2019 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2020/017335 | 1/23/2020 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 9714626 | Hatanaka | Jul 2017 | B2 |
| 10161339 | Kusakabe | Dec 2018 | B2 |
| 10634083 | Kusakabe | Apr 2020 | B2 |
| 10704486 | Kusakabe | Jul 2020 | B2 |
| 11181067 | Kato | Nov 2021 | B1 |
| 20150377176 | Hatanaka | Dec 2015 | A1 |
| 20180003120 | Nakano | Jan 2018 | A1 |
| 20180010545 | Mukaihara | Jan 2018 | A1 |
| 20180017005 | Kusakabe | Jan 2018 | A1 |
| 20180283306 | Kusakabe | Oct 2018 | A1 |
| 20190085783 | Kusakabe | Mar 2019 | A1 |
| Number | Date | Country |
|---|---|---|
| 2004-270531 | Sep 2004 | JP |
| 2014-152697 | Aug 2014 | JP |
| 2014-234923 | Dec 2014 | JP |
| 2016-196893 | Nov 2016 | JP |
| 2018-059511 | Apr 2018 | JP |
| WO-2016136394 | Sep 2016 | WO |
| Entry |
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| International Search Report with English translation and Written Opinion issued in corresponding application No. PCT/JP2019/026563 dated Oct. 29, 2019. |
| Number | Date | Country | |
|---|---|---|---|
| 20210164414 A1 | Jun 2021 | US |
