JPH0331580A - Radial plunger pump - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is used as a hydraulic pump that drives a plurality of different systems such as power steering and brake systems, and as a fuel injection pump that injects fuel. This relates to a radial plunger pump.

[Conventional technology]

Conventionally, there is a radial plunger pump that performs multiple discharges with one unit, such as the one shown in Japanese Patent Application Laid-Open No. 173372/1983, in which a plurality of discharge ports are provided in the pump housing, and each of the plurality of discharge ports is provided with a plurality of discharge ports. A fluid path is provided in which at least one of the cylinders in the discharge stroke communicates with each other, so that one pump can supply working fluid to a plurality of different systems of devices.

[Problem to be solved by the invention]

However, in this conventional device, as shown in FIG. 10, when the cylinder communicating with the discharge groove 200 on the left end side is in the discharge stroke, the discharge pressure is on the discharge groove 200 during the discharge stroke. P+, other discharge groove 20'2, 204.206
A residual pressure P2 is acting on the top. Leakage of fluid from the discharge groove during the discharge stroke b: length of the groove, δ: clearance between the pintle valve and bushier, L: distance between the grooves and the end of the pintle valve, ΔP: groove and groove, and the pressure difference between the groove and the end of the bottle pulp, μ: the viscosity coefficient of the operating body, so the discharge groove 20 during the discharge stroke in FIG.
If the leakage amount from 0 is 91, then bδ” (2P+
Pt) As shown in FIG. 11, when the cylinder communicating with the discharge grooves (202 or 204) other than the left and right ends is in the discharge stroke, the amount of leakage from the discharge groove 202 during the discharge stroke is 92. 1, the amount of leakage from the discharge grooves 200, 206 at the left and right ends is q+, and the amount of leakage from the discharge grooves 202 and 204 at the left and right ends is q! However, since P t > P z,
q'l＞q! Therefore, the discharge grooves at the left and right ends are 200°2゛06
・Amount of leakage from and discharge groove 202゜2゛0 other than left and right ends
There is a difference in the amount of leakage from 4. The discharge amount Qi from each cylinder is the difference between the stroke volume V and the leakage amount qi, (Qi=V
-qi), there is also a difference in the discharge amount from the left and right ends and cylinders other than the left and right ends. In a radial plunger pump, if there is a difference in the discharge amount from each cylinder, for example, when used as a fuel injection pump, there is a problem that the fuel injection amount is not uniform.

The present invention was made in view of the above problems, and an object of the present invention is to provide a radial plunger pump that can equalize the discharge amount of each cylinder.

[Means to solve the problem]

In order to achieve the above object, in the present invention, a rotor having a plurality of radially provided cylinders is built into a housing, and a plurality of plungers that come into contact with a cam ring provided on the inner surface of the housing are arranged in the cylinders of the rotor. By making the rotor and the cam ring eccentric, the rotor rotates.
In a radial plunger pump that makes the plunger reciprocate a few times (one reciprocation at a time), a discharge port provided in the housing for discharging a working fluid, and a plurality of fluid paths communicating between the discharge port and at least one of the cylinders in a discharge stroke. and a communication chamber that communicates with the fluid path that is in communication with the cylinder that is in the discharge stroke when the working fluid is discharged from the discharge port.

[Effect]

In the present invention configured as described above, when the working fluid is discharged from the discharge port, a part of the pressure of the working fluid acting on the fluid path is communicated with the fluid path that is in communication with the cylinder in the discharge process. lead to the room.

〔Example〕

A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of the radial plunger pump of this embodiment.
Figure 2 is a sectional view taken along line A-A in Figure 1, and Figures 3 to 8 are BB, GG, CC, and D- of the main parts of Figure 1, respectively.
It is a sectional view taken along lines D, EE, and FF.

In FIG. 1, ``■'' is a shaft that rotates in response to a rotational force from an external power, and is supported by a bearing 2. - The bearing 2 is fixed to the rear housing 5 by a circlip 51.

A coupling plate 3 is fixed to the rotor 4 with screws (not shown), and one end is connected to the width across flats portion 1a of the shaft 1.
It is combined with A front housing 6 is fixed to the rear housing 5 with bolts (not shown), and forms the outside of the pump. An O-ring 52 is disposed between the rear housing 5 and the front housing 6 to prevent fluid from leaking from inside the pump. An oil seal 53 is built into the rear housing 5 and is in contact with the cylindrical surface 1b of the shaft 1 to prevent leakage of fluid inside the pump. 8 is a bottle valve,
It is fixed to the front housing 6 with a gasket 54 with bolts (not shown). 4 is a rotor, and a cylindrical bushing 7 is press-fitted into an inner bearing hole of the rotor, and the rotor is rotatably mounted around a bottle valve 8 as an axis. The rotor 4 is connected to the shaft l via the coupling plate 3.
Rotates by receiving force from. As shown in FIG. 2, the rotor 4 is provided with cylinders 9a to 9d radially around the bottle valve 8, each having a plunger 10.
a to 10d are slidably incorporated. The heads of the plungers 10a to 10d are hemispherical and are slidably attached to shoes 14a to 14d having hemispherical recesses, and both are pressed against an outer bearing 15 by compression springs 13a to 13d. . The plungers 10a to 10d are provided with several annular pressure balance grooves (not shown) in order to maintain pressure balance. Further, the shoes 14a to 14d have protrusions 14a-1 to 14d- for lateral positioning of the rotor 4 and the bearing 15.
■ is provided. A cam ring 55 has a bearing 15 press-fitted therein, and can be moved around a pin 56 attached to the front housing 6 as an axis.

A joint 57 is rotatably incorporated into the cam ring 55, and a shaft 58 is attached to the joint 57 by screwing. Since the position of the joint 57 of the cam ring 55 is moved by the rotation of the shaft 58, the cam ring 55 can be moved about the pin 56 as an axis. The shaft 58 can be rotated by a motor 59 capable of forward and reverse rotation. On the surface of the bottle valve 8, there are discharge grooves 16a, 16b, as shown in FIGS. 5 to 8.
16 c.

16d, suction grooves 19a, 19b, 19c, 19d, and as shown in FIGS. A discharge passage 18ax18d and communication holes 17a to 17d are provided as part of the fluid path. The suction grooves 19a to 19d all communicate with the suction passage 20, and the discharge grooves 16a to 16d communicate with the discharge passages 18a to 18d through communication holes 17a to 17d, respectively. The suction passage 20 communicates with a suction port 22 provided in the front housing 6, and the discharge passages 18a to 18a.
18d communicate with a discharge port 21a provided in the front housing 6 and discharge ports 21b to 21d (not shown), respectively. The rotor 4 has a pressure introduction passage 11a and a pressure introduction passage 23a communicating with the cylinder 9a, a pressure introduction passage 23b communicating with the cylinder 9b, a pressure introduction passage 23c communicating with the cylinder 9c, and a communication passage 11d communicating with the cylinder 9d. A path 23d is provided. The cylinder 9a can communicate with the discharge groove 16a and the suction groove 19a through the communication passage 11a and the first communication hole 24a provided in the bushing 7, and also communicates with the pressure introduction passage 23a and the second communication hole 25a provided in the bushing 7. It is possible to communicate with the pressure introduction groove 31 as a communication chamber through the . In this case, the communication passage lla, the first communication hole 24a, the discharge groove) 6a, the communication hole 17a, and the discharge passage 18a form a fluid path,
The same suction groove 1 applies to the other cylinders 9b, 9c, and 9d.
9c, and can also communicate with the pressure introduction groove 31 through the pressure introduction path 23c and the second communication hole 25c provided in the bush 7. FIG. 9 shows the communication passage lid and pressure introduction passage 23b communicating with the cylinders 9b and 9d, with the rotor 4 rotated 270 degrees clockwise from FIG.

FIG. 23 is a diagram schematically showing the state of 23d. In FIG. 9, the cylinder 9b can communicate with the discharge groove 16b and the suction groove 19b through the first communication hole 24b provided in the bushing 7, and can communicate with the pressure introduction path 23b and the second communication hole 24b provided in the bushing 7. Through the hole 25b, the pressure introduction groove 3
It is possible to communicate with 0. The cylinder 9d has a communication path l
id and the first communication hole 24d provided in the bushing 7, it is possible to communicate with the discharge groove 16d and the suction groove 19d. It is possible to communicate with 30.

Next, the operation of this embodiment will be explained.

First, the suction and discharge action will be explained. As shown in Figure 2, when the rotor 4 rotates clockwise with eccentricity between the center axis of the cam ring 55 and the center axis of the bottle valve 8, each plunger slides on each cylinder, and as shown in the figure. The volume inside the cylinder is minimum on the horizontal right side, and the volume inside the cylinder is maximum on the horizontal left side. Therefore, rotor 4
Since the cylinder rotates clockwise, the volume inside the cylinder gradually increases on the horizontally lower side and gradually decreases on the horizontally upper side.

At this time, the first communication holes 24a to 2 provided in the bushing 7
4d communicates with the suction grooves 19a to 19d, respectively, on the horizontal lower side, and communicates with the discharge grooves 16a-16d, respectively, on the horizontal upper side, so fluid is sucked into each cylinder on the horizontal lower side, and fluid is sucked into each cylinder on the horizontal upper side. Fluid is discharged from. Since each cylinder communicates with a separate discharge groove, the fluid discharged from each cylinder is discharged from a separate discharge port. The discharge amount from each cylinder is determined by the cam ring 55.
It can be changed by moving. If it is desired to increase the discharge amount, the motor 59 rotates to move the cam ring 55 to the side where the eccentricity increases (to the left in the figure), thereby increasing the discharge amount.

Further, when it is desired to decrease the discharge amount, by rotating the motor 59 in the opposite direction to the above, the cam ring 55 moves to the side where the eccentricity decreases (to the right in the figure), and the discharge amount decreases.

Next, the pressure distribution on the bottle pulp discharge side during the discharge stroke of the cylinders 9a and 9b in this example is as follows.
2 and 13, when the cylinder 9a is in the discharge stroke as shown in FIG. 12, the discharge groove 16a and the pressure introduction groove 3
1, the discharge pressure P1 acts on the other discharge grooves 16b, 16.
A residual pressure P2 acts on the pressure introduction grooves 30 and 30c, 16d, and the other pressure introduction groove 30. Also, as shown in Fig. 13, cylinder 9
b is in the discharge stroke, the discharge pressure P1 acts on the discharge groove 16b and the pressure introduction groove 30, and the other discharge groove 16a
, 16c, 16d and the other pressure introduction groove 31 have residual pressure P! is working.

In this case, the fluid discharged from the cylinder 9a leaks from the discharge groove 16a and the pressure introduction groove 31, and the fluid discharged from the cylinder 9b leaks from the discharge groove 16b and the pressure introduction groove 30, respectively, but the amount of leakage is the same. Become. Therefore, the amount of leakage from all the discharge grooves (16a, 16b, 16c, 16d) becomes uniform, and therefore the amount of discharge from each cylinder becomes uniform.

As described above, according to this embodiment, by providing pressure introduction grooves on both sides of the plurality of discharge groove rows, the amount of leakage in each discharge groove during discharge is made uniform, and the discharge from each of the plurality of cylinders is The amount can be made uniform.

In this embodiment, the number of cylinders communicating with the fluid path is not limited to one, and one fluid path may communicate with a plurality of cylinder holes. In addition, the number of discharge ports may be plural or one, and furthermore, since the pressure introduction groove as a communication chamber is for guiding a part of the pressure of the working fluid, the shape of the groove is limited to that of this example. Not done.

Next, a second embodiment of the present invention is shown in FIGS. 14 and 15. In the first embodiment described above, the pressure introduction passage 2 for communicating the cylinder and the pressure introduction groove 30, 31 as a communication chamber.
3a, 23b, 23c, and 23d were provided on the rotor 4,
In this embodiment, pressure introduction paths 23a, 23b, 23c, 2
3d on the bushing 7, the cylinder and the pressure introduction grooves 30 and 31 are communicated with each other. Additionally, a communication path 11a and a lid are also provided in the bushing 7 accordingly.

Further, in the embodiment described above, the eccentricity of the cam ring 55 with respect to the rotor 4 for changing the discharge amount may be controlled by other actuators such as hydraulic pressure or a solenoid.

Next, FIG. 16 shows an application example in which the radial plunger pump of the present invention is used as a fuel injection pump that supplies fuel to an internal combustion engine.

This is an example in which the radial plunger pump of the present invention is applied to a 4-stroke, 4-cylinder engine, with pulley A109. If the radial plunger pump 101 of this embodiment is driven by reducing the engine speed to 1/2 using the pulley BIIO and the timing belt 104, the injection nozzle can be independently injected into each cylinder of the engine 103 in synchronization with the engine rotation. 102a
, 102b, 102c, and 102d.

At this time, due to the effect of the present invention, the amount of injection from each injection nozzle becomes uniform.

〔Effect of the invention〕

As explained above, according to the present invention, the leakage of working fluid from the fluid path during the discharge stroke is the same in all fluid paths, and therefore the excellent effect that the discharge amount of each cylinder can be made uniform is achieved. play.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. 1, and FIG. 3 is a sectional view taken along line BB of FIG.
4 is a sectional view taken along the line G-G of the main part of Fig. 1, Fig. 5 is a sectional view taken along the line C-C of the main part of Fig. 1, and Fig. 6 is a sectional view of the main part of Fig. 1. 7 is a cross-sectional view taken along line D-D of FIG.
8 is a sectional view taken along the line F-F of the main part in Fig. 1, and Fig. 9 schematically shows the main part in a state where the rotor has rotated 270 degrees clockwise from the state shown in Fig. 1. Figures 10 and 11 are diagrams showing the distribution of pressure acting on the discharge groove and its vicinity in a conventional radial plunger pump.
13 and 13 are diagrams showing the distribution of pressure acting on the discharge groove and its vicinity in the first embodiment of the present invention, and FIGS. 14 and 15 are cross-sectional views showing the main parts of the second embodiment of the present invention. figure,
FIG. 16 is a diagram showing an example of application of the present invention to a fuel injection pump. 4...Rotor, 5...Rear housing, 6...Front housing, 9a, 9b, 9c, 9d...Cylinder, 10a, 10b, 10c, 10d...Plunge+, lla, lld...・Communication path, 16a, 16b. 16c, 16d"-discharge groove, 17a, 17b, 17c+
17a... communicating hole, 18 a, 18 b,
l 8 c. 18d...Discharge passage, 21a...Discharge port, 24a,
24b, 24c, 24d...first communication hole, 30.31
...Communication room, 55...Cam ring, 23a, 23
b. 23C, 23d...pressure introduction path + 25 a,
25b. 25c, 25d - second communication hole.

Claims (1)

[Claims] A rotor having a plurality of radially arranged cylinders is built into a housing, and a plurality of plungers that abut a cam ring provided on the inner surface of the housing are slidably inserted into cylinder holes of the rotor. A radial plunger pump that makes the plunger reciprocate at least once per rotation of the rotor by eccentrically inserting the rotor and the cam ring, comprising: a discharge port provided in the housing and discharging working fluid; the discharge port and the discharge port; a plurality of fluid paths that communicate with at least one of the cylinders that are in the stroke; and a communication chamber that communicates with the fluid path that is in communication with the cylinder that is in the discharge stroke when the working fluid is discharged from the discharge port. A radial plunger pump comprising: