The present disclosure relates to an engine device including an engine and a case that accommodates the engine.
There is a known portable engine power equipment configured such that an engine and a power equipment driven by the engine are accommodated in a case made of synthetic resin and a carrying handle is provided at an upper part of the case (for example, Patent Document 1). In this engine power equipment, a crankcase, a cylinder block and a cylinder head of the engine are covered by a shroud, and a head cover of the engine is exposed via an opening formed in an upper part of the shroud so as to be elastically supported by the carrying handle of the case. Accordingly, when the carrying handle is grasped and the engine power equipment is lifted, the loads of the engine and the power equipment act directly on the carrying handle.
Patent Document 1: JP2001-27127A
However, the engine power equipment described in Patent Document 1 has the following problems. The crankcase of the engine is divided into a front half and a rear half on a dividing face inclined with respect to an axis of a crankshaft. The front half is formed integrally with the cylinder block and the cylinder head, and the front half and the rear half are joined by bolts. On the other hand, a lower support structure of the engine is configured such that an attachment bracket is joined to a lower part of the rear half of the crankcase by two bolts extending in parallel with the axis of the crankshaft, and the attachment bracket is supported by the case. Therefore, a space for providing the lower support structure is required on a rear side of the engine, and accordingly, a space inside the case may be reduced or the case needs to be enlarged.
In view of such a problem of the prior art, the present invention provides an engine device that can enlarge a space inside a case without lowering support stiffness.
To achieve such an object, the present invention provides an engine device (1) including: an engine (2); and a case (11) that accommodates the engine, wherein the engine includes a crankcase (46) constituting a lower part thereof and is attached to the case via support parts (81, 82), at least one of the support parts includes a mounting part (11b) provided in the case and an attachment bracket (91) fastened to a bottom of the crankcase by a fastening bolt (90) and attached to the mounting part, and the fastening bolt (90) penetrates through a through hole (92a) provided in the attachment bracket and is screwed into a screw hole (46e) formed obliquely inward at a corner of the bottom of the crankcase.
According to this configuration, the fastening bolt and the attachment bracket are displaced downward, and a space inside the case is enlarged accordingly. Further, since the screw hole is formed at the corner of the bottom of the crankcase, which has high stiffness, supporting stiffness does not decrease.
Preferably, in the above configuration, the crankcase (46) includes a first half (46c) and a second half (46d) joined to each other by bolts (52) on an interface (46b) formed obliquely with respect to a crank axis, and the second half is provided with the screw hole (46e), and the screw hole is orthogonal to the interface.
According to this configuration, the direction of the screw hole is orthogonal to the interface like a through hole of a bolt for fastening the second half to the first half is orthogonal thereto, so that the screw hole can be formed easily.
Preferably, in the above configuration, the attachment bracket (91) is attached to the mounting part via a mounting axial member (95, 96) penetrating horizontally through an attachment hole (93a) provided in the attachment bracket and a support hole (11d) provided in the mounting part (11b), and the mounting axial member at least partially overlaps with the fastening bolt when viewed in an axial direction of the fastening bolt (90).
According to this configuration, the load transmitted from the engine to the attachment bracket via the fastening bolt is linearly transmitted to the mounting bolt. Therefore, the bending moment acting on the attachment bracket becomes small, and the bending moment acting on the fastening bolt and the screw hole also becomes small. Accordingly, it is possible to prevent the support stiffness from being lowered.
Preferably, in the above configuration, the mounting part (11b) is provided at each of two ends of the mounting axial member (95, 96), the attachment bracket (91) includes two cylindrical parts (93) surrounding a middle part of the mounting axial member between the two ends thereof, and each cylindrical part is supported by the mounting axial member via a rubber bushing (94) provided between an outer circumference of the mounting axial member (95, 96) and an inner circumference of the cylindrical part.
According to this configuration, it is possible to prevent the vibration of the engine from being transmitted to the case.
Preferably, in the above configuration, the through hole (92a) is provided in a part of the attachment bracket (91) between the two cylindrical parts (93).
According to this configuration, it is possible to prevent the size of the attachment bracket from increasing.
Preferably, in the above configuration, the mounting axial member (95, 96) includes a mounting bolt (96) and a collar (95) surrounding the mounting bolt.
According to this configuration, it is possible to prevent the rubber bushing from being pressed against the mounting bolt when the mounting bolt is tightened.
Preferably, in the above configuration, the engine device further includes a muffler (61) accommodating an exhaust catalyst (62) and provided in a space defined between the case (11) and a side of the engine (2) where the attachment bracket (91) is attached.
According to this configuration, the muffler accommodating the exhaust catalyst is provided in the space enlarged owing to the above arrangement of the attachment bracket, so that the size of the muffler can be increased. Accordingly, it possible to increase the size of the exhaust catalyst and thereby improve the purification performance of the exhaust gas without reducing the muffling effect of the muffler.
Thus, according to the present invention, it is possible to provide an engine device that can enlarge a space inside a case without lowering support stiffness.
In the following, an embodiment of the present invention will be described in detail with reference to the drawings.
As shown in
The case 11 includes a left side cover 12, a right side cover 13, a front cover 14, a rear cover 15, and an under cover 16. The left side cover 12 and the right side cover 13 are integrally joined to each other, and a carrying handle 17 for carrying the engine generator 1 is formed in the upper parts of the left side cover 12 and the right side cover 13. A lattice-like reinforcement rib 17a is formed inside the carrying handle 17 (see
Left and right reinforcement frames 26 (only the left reinforcement frame 26 is shown in
As shown in
Thus, the fuel tank 32 is interposed laterally between the left side cover 12 and the right side cover 13 so as to be supported by the left side cover 12 and the right side cover 13. Therefore, the fuel tank 32 can be attached/detached by separating the left side cover 12 and the right side cover 13. Moreover, the fuel tank 32 is surrounded by the left and right reinforcement frames 26, so that the fuel tank 32 can be protected from an impact applied from the outside. The left and right reinforcement frames 26 do not cover the entire engine generator 1, so that the weight is not significantly increased.
As shown in
A fuel tube 37 that supplies fuel to the fuel cock 36 is connected to the bottom of the fuel tank 32, a fuel tube 38 that supplies fuel to the fuel pump 35 is connected to the fuel cock 36, and a fuel tube 39 that supplies fuel to a carburetor 41 arranged at a right side surface of a cylinder head 50 of the engine 2 is connected to the fuel pump 35. A pulsation of an internal pressure of a crankcase of the engine 2 is transmitted to a diaphragm inside the fuel pump 35, so that the fuel pump 35 operates.
Next, the structure of the power generation unit 4 will be described. As shown in
The crankcase 46 has a two-part structure and includes an upper half 46c that mainly constitutes a front half and a lower half 46d that mainly constitutes a rear half. The upper half 46c and the lower half 46d are joined to each other by bolts 52 on an interface 46b which is inclined rearward and upward by about 50° with respect to the axis of the crankshaft 45. The upper half 46c of the crankcase 46 is integrally formed with the cylinder block 47 and the cylinder head 50, and rotatably supports a front end side of the crankshaft 45 via a ball bearing. The lower half 46d of the crankcase 46 rotatably supports a rear end side of the crankshaft 45 via a ball bearing.
A lower part of the crank chamber 46a defines an oil reservoir. An oil level sensor 78 is attached to a bottom wall of the crankcase 46. A centrifugal governor 79 for speed control is attached to a rear wall of the crankcase 46 behind the oil level sensor 78. The centrifugal governor 79 is provided with a rotating disk rotatably supported by a support shaft fixed to an inner surface of the lower half 46d of the crankcase 46, and a driven gear and a lubricating oil splashing blade are integrally formed on an outer circumference of the rotating disk.
The head cover 51 includes an ignition plug attachment/detachment hole 51b, and is detachably joined to the cylinder head 50 by four bolts 53 (see
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As shown in
A recoil starter 75 is fixed to an opening formed at a front end of the fan cover 71 by bolts. The recoil starter 75 includes a reel, an operation cable, and a driving member. The reel is rotatably supported by a recoil starter cover. One end side of the operation cable is wound around the reel, and another end side of the operation cable penetrates through the right reinforcement frame 26 and the right side cover 13. The driving member is provided on the reel and detachably engaged with a driven member integrated with the cooling fan 57. When the operation cable is pulled and the reel is rotated, the driving member is engaged with the driven member so as to rotate the cooling fan 57, and thereby the crankshaft 45 connected to the cooling fan 57 via the flywheel 55 is cranked, so that the engine 2 can be started.
When the engine 2 is started, the cooling fan 57 provided on the flywheel 55 of the generator 3 rotates in the shroud 66. Due to the negative pressure generated by the rotation of the cooling fan 57, the outside air passes through the air introduction opening 14a (see
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First, the upper portion support part 81 will be described. A support plate 51c extending in the fore and aft direction protrudes on an upper surface of the head cover 51 of the engine 2. A pair of left and right rubber bushings 85 are fitted to a circular support hole 51d formed in the center of the support plate 51c, and a collar 86 is inserted into the pair of left and right rubber bushings 85. In a state where washers 88 are arranged at both ends of the pair of left and right rubber bushings 85, both ends of a connecting pin 89 penetrating through the washers 88 and the collar 86 are fitted to a pair of attachment bosses 11a as mounting parts (see
Next, the rear lower portion support part 82 will be described. As shown in
The attachment bracket 91 includes a main part 92 having two through holes 92a through which the fastening bolts 90 penetrate and two cylindrical parts 93 extending obliquely downward and rearward from the main part 92 and protruding to the outside of the shroud 66 from an opening 66b formed in a rear lower part of the shroud 66. Each of the cylindrical parts 93 defines an attachment hole 93a having an axis extending laterally. The attachment bracket 91 supports the shroud 66 by holding an edge of the opening 66b of the shroud 66 by the cylindrical parts 93. The two cylindrical parts 93 are separated by a notch 93b provided on the axes 90X of the fastening bolts 90. The two cylindrical parts 93 are integrated with each other on a side of the main part 92, namely, on a side excluding the notch 93b. The notch 93b has a size to allow penetration of the fastening bolts 90 and entry of a tool that engages with the heads of the fastening bolts 90 when the fastening bolts 90 are attached/detached. That is, the two through holes 92a are provided in a part of the main part 92 corresponding to the notch 93b (a part of the main part 92 between the two cylindrical parts 93). Accordingly, it is possible to prevent the size of the attachment bracket 91 from increasing. A pair of left and right cylindrical rubber bushings 94 are fitted to the cylindrical parts 93 such that a part of each rubber bushing 94 in the axial direction is inserted into each cylindrical part 93.
On a lower rear side of the case 11, a pair of left and right attachment ribs 11b as mounting parts are formed so as to protrude upward from a rear upper surface of the under cover 16. A collar 95 is inserted into support holes 11d provided in the pair of attachment ribs 11b so that both ends of the collar 95 are supported by the support holes 11d. The pair of rubber bushings 94 are interposed between a pair of left and right washers 98 and supported on an outer circumference of a middle portion of the collar 95. A mounting bolt 96, which is inserted from the attachment boss 11a formed in the right side cover 13, penetrates through the collar 95. The mounting bolt 96 is fastened to an embedded nut 97 provided in the attachment boss 11a formed in the left side cover 12. Accordingly, the attachment bracket 91 exposed from the shroud 66 is elastically supported by the under cover 16 via the rubber bushings 94. Thereby, it is possible to prevent the vibration of the engine 2 from being transmitted to the case 11. Further, the collar 95 is provided inside the rubber bushings 94, and the mounting bolt 96 is provided in the collar 95. Thereby, the rubber bushings 94 are not pressed against the mounting bolt 96 when the mounting bolt 96 is tightened. Therefore, the mounting bolt 96 can be securely fastened to the embedded nut 97.
The mounting bolt 96 and the collar 95 surrounding the mounting bolt 96 extend in the horizontal direction (the direction orthogonal to the vertical plane including an axis of the cylinder 47a). The two cylindrical parts 93 surround the axial middle parts of the mounting bolt 96 and the collar 95, and are attached to the attachment bosses 11a via the mounting bolt 96 and the collar 95. The axes 90X of the fastening bolts 90 are orthogonal to the interface 46b (see
The front lower portion support part 83 will be described. As shown in
As shown in
As shown in
On the other hand, in a state where the engine generator 1 is placed on the ground or the floor, most of the load of the power generation unit 4 is directly transmitted to the under cover 16 provided with the support legs 21. Therefore, even if the stiffness of the left side cover 12 and the right side cover 13 is set to be low, the deformation due to the load does not occur.
Further, the power generation unit 4 is elastically supported by the case 11 at three parts of the upper portion support part 81, the rear lower portion support part 82, and the front lower portion support part 83, so that the load of the power generation unit 4 is dispersed to each part of the case 11. Moreover, according to the vibration absorbing effect of the rubber bushings 85, 94, 94, it is possible to suppress not only the transmission of the vibration from the engine 2 to the carrying handle 17 but also the resonance of the case 11 due to the vibration of the engine 2.
In a state where the engine generator 1 is placed on the ground or the floor, the left side cover 12 and the right side cover 13 can be separated from the under cover 16 by simply removing the four bolts 29, 96. Therefore, the engine 2 and the generator 3 can be exposed and easily maintained without bedding the engine generator 1.
In the engine generator 1 of the present embodiment, the fastening bolts 90 that fasten the attachment bracket 91 to the crankcase 46 penetrate through the through holes 92a of the attachment bracket 91 and are screwed into the screw holes 46e formed obliquely inward at the corner of the bottom of the crankcase 46. Therefore, it is possible to enlarge the space inside the case 11 without lowering the support stiffness of the rear lower portion support part 82. That is, as shown by imaginary lines in
Concrete embodiments of the present invention have been described in the foregoing, but the present invention should not be limited by the foregoing embodiments and various modifications and alterations are possible. For example, in the above embodiments, the present invention is applied to the engine generator 1. However, the present invention may be applied to other engine power equipment such as an engine pump and a construction machine, or may be applied to an engine device including an engine for driving power equipment separated therefrom. Also, a specific configuration, an arrangement, quantity, an angle, and the like of each member and each portion thereof can be changed as appropriate within the scope of the present invention. Further, not all of the structural elements shown in the above embodiments are necessarily indispensable and they may be selectively adopted as appropriate.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2017/044444 | 12/11/2017 | WO | 00 |