The present disclosure relates; to check valves. More particularly, the present disclosure relates to a check valve which is suitable for use in vacuum or pressure pumps and is characterized by reduced operational noise.
Hybrid and electric vehicles in which the conventional internal combustion engine has been replaced with alternative propulsion technologies must use an alternative source of vacuum pressure for brake-boosted systems. The most common approach to provide vacuum pressure is by way of a stand-alone electric-driven vacuum pump. Vacuum pumps, however, are known to generate objectionable noise.
A common type of conventional vacuum pump includes a pump housing which contains a chamber in which reciprocates a piston. A suction check valve is provided between a suction conduit and the inlet of the chamber. A discharge check valve is provided between the outlet of the chamber and an exhaust conduit. Each of the suction check valve and the discharge check valve typically includes a valve body through which extends multiple discharge port openings of equal size or diameter. A flexible valve disk is positioned adjacent to the valve body.
In operation of the suction check valve, as the piston is displaced in one direction in the chamber, air flows from the suction conduit through the discharge port openings and against the valve disk, respectively, of the suction check valve to dislodge the valve disk from the valve body and thereby facilitate flow of the air into the chamber. This generates negative pressure in the suction conduit. At this time, the exhaust check valve remains closed as the valve disk engages the valve body of the exhaust check valve. As the piston is subsequently displaced in the opposite direction in the chamber, the suction check valve closes as the valve disk engages the valve body of the suction check valve. The air flows from the chamber through the open exhaust check valve and is discharged from the exhaust conduit. Due to the uniform diameter of the discharge port openings in the valve body of each of the suction check valve and the exhaust check valve, a noise is generated when each check valve closes as the valve disk engages the valve body.
The present disclosure is generally directed to a check valve. An illustrative embodiment of the check valve includes a valve body, a plurality of discharge port openings of non-uniform width extending through the valve body and a flexible valve disk disposed generally adjacent to the valve body.
The present invention is further generally directed to a vacuum pump. An illustrative embodiment of the vacuum pump includes a pump housing having a suction conduit, a discharge conduit and a chamber between the suction conduit and the discharge conduit; a piston reciprocally mounted in the chamber; a motor engaging the piston; a suction check valve disposed between the suction conduit and the chamber; and a discharge check valve disposed between the chamber and the discharge conduit. Each of the suction check valve and the discharge check valve includes a valve body, a plurality of discharge port openings of non-uniform width extending through the valve body and a flexible valve disk disposed generally adjacent to the valve body.
The present disclosure is further generally directed to a method of reducing noise in a vacuum pump having a suction conduit, a discharge conduit, a chamber between the suction conduit and the discharge conduit and a piston reciprocally mounted in the chamber. An illustrative embodiment of the method includes providing a suction check valve between the suction conduit and the chamber and providing a discharge check valve between the chamber and the discharge conduit. Each of the suction check valve and the discharge check valve includes a valve body, a plurality of discharge port openings of non-uniform width and position extending through the valve body and a flexible valve disk disposed generally adjacent to the valve body.
The disclosure will now be made, by way of example, with reference to the accompanying drawings, in which:
Referring initially to
The vacuum pump 20 may have a conventional design and typically includes a pump housing 21 having a chamber 26. A piston 24 is reciprocally mounted in the chamber 26. A suction conduit 22 and a discharge conduit 36 are disposed in pneumatic communication with the chamber 26. A suction check valve 1a is provided in the pump housing 21 between the suction conduit 22 and the discharge conduit 36. A discharge check valve 1b is provided in the pump housing 21 between the discharge conduit 36 and the chamber 26. The design of the suction check valve 1a and the discharge check valve 1b will be hereinafter described. At least one filter 23 is typically provided between the suction conduit 22 and the suction check valve 1a.
A connecting rod 28 engages the piston 24. An electric motor 32 is provided in the pump housing 21 and has a drive shaft 33 which engages the connecting rod 28 through an eccentric cam 34. Accordingly, by operation of the motor 32, the drive shaft 33 rotates the cam 34, which reciprocates the connecting rod 28. The connecting rod 28, in turn, reciprocates the piston 24 in the chamber 26.
Referring next to
The check valve 1 includes a valve disk 10 which is disposed adjacent to the valve body 2. As shown in
Referring next to
As the piston 24 (via actuation of the motor 32, drive shaft 33 and connecting rod 28 shown in
As the piston 24 slides in the chamber 26 in the direction indicated by the arrow in
Upon closing of the discharge check valve 1b at the beginning of movement of the piston 24 shown in
While the illustrative embodiments of the disclosure have been described above, it will be recognized and understood that various modifications can be made to the embodiments and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the disclosure.
Number | Name | Date | Kind |
---|---|---|---|
3327731 | Kehler | Jun 1967 | A |
3360006 | Kehler | Dec 1967 | A |
3403696 | Pynchon | Oct 1968 | A |
3463184 | Kohler et al. | Aug 1969 | A |
3508849 | Weber | Apr 1970 | A |
3961868 | Droege et al. | Jun 1976 | A |
3981636 | Aoki et al. | Sep 1976 | A |
4344346 | Erickson et al. | Aug 1982 | A |
4402342 | Paget | Sep 1983 | A |
4643220 | Hartshorn | Feb 1987 | A |
4856558 | Kardos | Aug 1989 | A |
4913187 | Woollatt et al. | Apr 1990 | A |
6510868 | Penza | Jan 2003 | B2 |
Number | Date | Country |
---|---|---|
0814603.7 | Aug 2008 | GB |
2005-337208 | Dec 2005 | JP |
Number | Date | Country | |
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20090050217 A1 | Feb 2009 | US |