JPH03168368A - Radial plunger pump - Google Patents

Abstract

PURPOSE:To uniform the discharge quantities from respective cylinders by providing a distribution disk which integrally rotates with a rotor and has openings for communicating distribution discharge passage with a discharge port in a prescribed position while sliding with a pintle valve. CONSTITUTION:A distribution discharge passage 24a communicated with a common discharge passage 23a which has been provided inside a pintle valve 23 is communicated with a communicating hole 22a being an opening of U-shape, in section, which is provided in a distribution disk 22, at the thrust plane 23b of the valve 23, and also the communicating passage 22a inside the distribution disk 22 is communicated with any of the injection ports 51a to 51d provided on the valve 23 side to constitute a fluid passage. And, the injection ports 51a to 51d are arranged at intervals of 90 deg.C, and by the disk 22 rotating with a rotor 8, the distribution discharge passage 24a of the valve 23 is successively communicated with the injection ports in the order 51a 51b 51c 51d. And the operating fluid being sent from a plurality of plungers 10a to 10d is rotatingly distributed while being sealed with the disk 22.

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, or as a fuel injection pump that injects fuel. This relates to a radial plunger pump.

[Prior Art] Conventionally, there is a radial plunger pump that performs multiple discharges with one unit, for example, as shown in Japanese Patent Application Laid-Open No. 60-173372. For each of the multiple discharge ports,
A fluid path is provided through which at least one of the cylinders in the discharge stroke communicates with each other, so that one bomb can supply working fluid to a plurality of different systems.

[Problem to be solved by the invention]

However, in this conventional device, as shown in FIG. 9, which shows the distribution of the discharge pressure p acting on the pintle valve 207, when the cylinder communicating with the discharge port 200 on the left end side is in the discharge stroke, the discharge stroke A discharge pressure P acts on the inner discharge groove 200, and a residual pressure P2 acts on the other discharge grooves 202, 204, and 206. Generally, the amount of fluid leaking from the discharge groove during the discharge stroke is expressed as bδ3ΔP, where b: length of the groove. δ: Clearance between the pintle valve and the pusher, ΔP: Pressure difference between the grooves and between the groove and the end of the pintle valve, μ: Viscosity coefficient of the working fluid, L: Space between the grooves and the end of the groove and the pintle valve The interval is .

If the amount of leakage from the discharge groove 200 during the discharge stroke in FIG. 9 is q+, it becomes bδ' (2P.-p2), and as shown in FIG.
202 or 204) is in the discharge stroke and the amount of leakage from the discharge 7a202 during the discharge stroke is 92, then 2bδ' (P.-PK).

Therefore, the amount of leakage from the discharge grooves 200 and 206 at the left and right ends is q, and the amount of leakage from the discharge grooves 202204 other than the left and right ends is q2, but since P1 is larger than P2, q1
becomes larger than 92, and the discharge grooves 200, 206 at the left and right ends
There is a difference between the amount of leakage from the discharge grooves 202 and 204 other than the left and right ends. In addition, when a pump with a pintle structure as shown in Fig. 9 handles a particularly low-viscosity, high-pressure fluid, the plunger during discharge presses the rotor toward the pintle valve as shown in Fig. 11 with a force fp. , the shaft diameter of the pintle valve and the hole diameter of the rotor are different, as shown in FIG. 14, which is a sectional view taken along line A-A in FIG. There is a problem that the difference δ is biased toward the bottle discharge groove side, which promotes leakage from the discharge groove.The discharge volume Qi from each cylinder is determined by the stroke volume Qv and the leakage amount
(Qi = Qv - qi), so naturally there will be a difference in the discharge amount from the plurality of cylinders.

If used as is as a fuel injection bomb, there was a problem in that the amount of fuel injected was not uniform.

The present invention has been made in view of the above problem δ,
It is an object of the present invention to provide a radial plunger pump that can equalize the discharge amount from 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 arranged 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 attached to the rotor. A radial plunger pump that is slidably inserted into each cylinder hole and makes the plunger reciprocate at least once per rotation of the rotor by eccentrically disposing the rotor and the cam ring. a discharge port fixed to the housing at the center of rotation of the rotor in a slidable manner relative to the rotor, and communicating with the cylinder hole at a predetermined position; and communicating with the common discharge passage; a pintle valve having therein a plurality of distribution discharge passages corresponding to the number of the cylinder holes; and a pintle valve that rotates integrally with the rotor and slides on the pintle valve to open the distribution discharge passage and the discharge port at a predetermined position. and a distribution disk having a communicating opening.

[Effect]

In the present invention having the above structure, the working fluid compressed within the cylinder is supplied to the common discharge passage and the distributed discharge passage inside the pintle valve. It is discharged from the outlet through the opening in the distribution disk.

〔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 bomb of this example.
Figure 2 is a sectional view taken along line A-A in Figure 1, and Figure 3 is a cross-sectional view taken along line B-- in Figure 2.
B sectional view and Figures 4 to 6 are respectively C- in Figure 3.
It is each sectional view of C, DD, and EH.

In FIG. 1, a shaft 1 rotates in response to a rotational force from an external power and is supported by a hair ring 2. As shown in FIG. The bearing 2 is fixed to the rear housing 27 by a circlip 26.

The coupling plate 3 is fixed to the rotor 8 by screws (not shown), and one end of the coupling plate 3 is fitted into the width across flat portion 1a of the shaft 1. The front housing 28 is fixed to the rear housing 27 with bolts (not shown).
It resembles the exterior of a bomb. front housing 28
A gasket 16 is installed between the pump and the rear housing 27 to prevent fluid from leaking from inside the pump. An oil seal 25 is built into the rear housing 27 and comes into contact with the cylindrical surface of the shaft 1 to prevent leakage of fluid inside the pump. The pintle valve 23 is fixed to the front housing 28 with a gasket 31 in between by bolts (not shown). 8 is a rotor, and a cylindrical pusher 9 is press-fitted into the inner bearing hole of the rotor 8.
It is rotatably mounted around the pintle valve 23 as an axis.

A distribution disk 2 made of a sliding member (for example, graphite) is attached to the rotor 8 through a 19.20 o ring on the thrust surface.
2 is press-fitted. A holder 21 on a ring is installed, receives rotational force from the rotor 8 through a pin (not shown), and rotates in synchronization with the rotor 8.

The pressure chamber 8a is shaped by the rotor 8 and the holder 21,
Sealed with O-ring 19.20. The pressure chamber 8a includes a communication passage 21a provided in the holder 21 and auxiliary pressure passages 4la provided in the pintle valve 23.
A portion of the discharge fluid sent from the plungers 10a to 10d is introduced through the plunger lb.

Therefore, the holder 21, which is built into the rotor 8 so as to be able to move slightly in the strus direction, generates a force that strongly presses the distribution disk 22 against the thrust plane 23b of the pintle valve 23, and the rotor 8 uses the reaction force to The pintle valve 23 is pushed to the left in the figure, so the pintle valve 23
A stopper disk 4, which is positioned with a pin 14 and fixed with a screw l3, prevents it from slipping off to the left. Further, the rotor 8 receives force from the shaft 1 via the coupling plate 3 and rotates. As shown in FIG. 2, cylinders 33a to 33d are provided in the rotor 8 radially around the bottle valve 23, and each plunger 10a to 10d is slidably incorporated therein. Plunger 10a = lo
The head of a has a hemispherical shape and is slidably assembled to shoes 12a to 12d having hemispherical recesses, and both are pressed against an outer bearing 15 by compression springs lla to 11d. Plunger 10a-1
Several annular pressure balance grooves (not shown) are cut in 0d to maintain pressure balance. A bearing 15 is press-fitted into the cam ring 17, and the cam ring 17 can be moved about a pin 18 attached to the front housing 28 as an axis. A joint 36 is rotatably incorporated into the cam ring 17, and a shaft 35 is attached to the joint 36 by screwing. The cam ring 17 can be moved around the bin 18 because the position of the joint 36 moves as the shaft 35 rotates. The shaft 35 can be rotated by a motor 34 capable of forward and reverse rotation. As shown in FIGS. 4 and 5, the bottle valve 23 has auxiliary pressure grooves 39a, 39b,
A discharge groove 42a, a suction groove 46a, and an auxiliary pressure hallance groove 48a are provided, and inside the pintle valve 23, a common discharge passage 23a. Distribution discharge passage 24a. Auxiliary pressure passages 41a, 41b, a communication hole 43a, and auxiliary communication holes 40a, 40b are provided as part of the fluid path, and auxiliary pressure grooves 39a, 39b and auxiliary pressure balance groove 48a are connected via auxiliary pressure passages 41a, 4lb. The configuration is such that they communicate with each other.

In addition, the suction groove 46a also passes through the communication holes 45a and 45b to the suction passage 44a. 44b.

The suction passages 44a and 44b become one within two days of the front housing and communicate with the suction union 30.

As shown in FIG. 3, after the working fluid sent from the plunger is discharged into the auxiliary pressure groove 39a, the communication passage 40
The steel balls 49 . Since it is also sent to the relief valve controlled by the spring 50 and the stopper 51, the pressure in the auxiliary pressure passage 41a is maintained at the pressure set by the relief valve, and the distribution disk 22 is moved to the thrust plane 23b of the pintle valve 23.
This generates a pressing force that creates a mechanical seal. Note that the auxiliary pressure groove 39a. Although the communication passage 40a has been described, the auxiliary pressure groove 39 not shown in FIG.
b and the communication path 40b have the same structure and function. The fluid passage established by this mechanical seal is, as shown in FIG.
4a communicates with a communication hole 22a, which is an opening with a U-shaped cross section, provided in the distribution disk 22 at the thrust surface 23b of the pintle valve 23, and further communicates with a communication hole 22a in the distribution disk 22, which is an opening with a U-shaped cross section. 22a communicates with any one of the injection ports 5la to 51d provided on the pintle valve 23 side. Further, as shown in FIG. 6, when there are four cylinders, the injection boats 51a to 51d are arranged every 90 degrees, and the
The distribution disk 22 rotating together with the distribution discharge passage 24a of the pintle valve 23 and the injection boat 51a
→ 5 1 b → 5 1 c-5 1 d are communicated in this order. In addition, in this FIG. 6, the communication path on the side of the distribution disk 22 is shown by a broken line.

The injection boats 51a to 51d communicate with discharge ports 29a to 29d provided on the second front housing, respectively. A nipple 29b is fitted into the discharge port 29a with a screw, and the nipple 29b is connected to a high-pressure pipe 29'd by a joint 29c, and the tip of the high-pressure pipe 29d is connected to an injection nozzle 32a. .

Next, the operation of this embodiment having the above structure will be explained.

First, the suction and discharge action will be explained. As shown in FIG. 2, when the rotor 8 rotates clockwise in a state where the center axis of the cam ring 17 and the center axis of the twenty dollar valve 23 are eccentric, each plunger 10a to 10d is moved to each cylinder 33a. - 33d, the volume inside the cylinders 33a-33d becomes the minimum on the horizontal right side in the figure, and the volume inside the cylinders 33a-33d becomes the maximum on the horizontal left side in the figure. In this embodiment, since the rotor 8 rotates clockwise, the volume inside the cylinders 33a to 33d gradually increases on the horizontal lower side and gradually decreases on the horizontal upper side. At this time, push 9
The communication holes 9a to 9d provided in the above communicate with the suction groove 46a on the horizontal lower side, and communicate with the auxiliary pressure grooves 39a and 39a on the horizontal upper side, respectively.
It communicates with the discharge groove 42a and then again with the auxiliary pressure groove 39b in this order.

Of this, the portion discharged into the auxiliary pressure grooves 39a and 39b is used for pressing the distribution disk 22, as described above.
The amount discharged into the discharge groove 42a is discharged from the injection nozzle 32a via the injection port 51a and the discharge port 29a.

Here, the operation of one plunger 10a and the switching operation of the distribution disk 22 will be explained in more detail using FIGS. 15 to 22. 15 to 18 are cross-sectional views taken along the line CC in FIG. 3, from the most fully extended position (TDC) to the most contracted position' (B D C ) of the plunger 10a. It is sectional drawing which showed the discharge process in order. Figures 19 to 22 show these 15
FIG. 19 is a cross-sectional view taken along line EE in FIG. 3, corresponding to FIGS. 18 to 18; In FIG. 15, the plunger 10a applies pressure to the auxiliary pressure groove 39a of the pintle valve 23 through the communication hole 9a of the pusher 9, and at this time, in FIG. It is connected to the previous injection ball l-51d. And the 16th
As shown in the figure, when the rotor 8 rotates 50 degrees from the TDC position, the communication hole 9a of the pusher 9 is connected to the pintle valve 2.
As shown in FIG.
2a and the injection boat 51a of the pintle valve 23 are completed, and discharge to the injection boat 51a begins. When the rotor 8 further rotates by 80 degrees and rotates to the position shown in FIG. 17, the communication between the communication hole 9a of the bunsch 9 and the discharge groove 42a of the pintle valve 23 ends, that is, the discharge ends and at the same time the auxiliary pressure The discharge shifts to the groove 39b, and as shown in FIG. 21, there is only a small amount of overlap between the communication hole 22a of the distribution disk 22 and the injection port 51a of the pintle valve 23, and the switching is about to occur.

Then, when the rotor rotates another 50 degrees as shown in FIG. 18, the plunger 10a reaches the BDC position and discharge is completely completed, and as shown in FIG.
The communication hole 22a of No. 2 is also completely switched to the next injection boat 5lb. Such a series of strokes is performed continuously for the plungers 10a to 10d arranged every 90 degrees, and the distributed discharge is completed.

Further, the amount of discharge from each cylinder can be changed depending on the amount of movement of the cam ring 17.

As explained above, according to this embodiment, the working fluid sent from the plurality of plungers is rotatably distributed while being sealed by the distribution disk that rotates in synchronization with the rotor, so that the plurality of injection ports are arranged on the same plane. At the same time, a pressure chamber is provided and the distribution disk is pressed against the housing, resulting in a flat seal structure with almost no gaps, resulting in less leakage and suppressing variations in leakage amount. This has the excellent effect of making the discharge amount from each cylinder uniform.

Next, a second embodiment of the present invention will be described using FIG. 7.

In FIG. 7, the same components as in the first embodiment are given the same reference numerals and their explanations will be omitted. In the first embodiment, the distribution disk 22 is connected to the pintle valve 23.
In the second embodiment, the necessary sealing pressure was generated by the pressure of the working fluid using an auxiliary pressure groove in a system separate from the discharge system to press the force against the flat part 23b.
The communication hole 71a of the holder 71 is different from the first embodiment in that the communication hole 71a of the holder 71 is configured so that the pressure in the distribution discharge passage 24a is directly guided to the pressure chamber 8a.

Therefore, it does not have a relief valve as described in the above-mentioned Embodiment ①. Furthermore, in the first and second embodiments, the amount of eccentricity of the cam ring 17 relative to the rotor 8 for changing the discharge amount may be controlled by an actuator such as hydraulic pressure or a solenoid.

Further, in both the first embodiment and the second embodiment, the pressure chamber 8
The area on which the pressure a acts is larger than the area of the communication hole 22a of the distribution disk 22, and this pressure difference leads to improved sealing performance.

Next, FIG. 8 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 bomb 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. 102
a. 102b, 102c. Fuel is injected from 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 the working fluid from the fluid path during the discharge stroke becomes equivalent 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 the drawing]

Fig. 1 is a sectional view showing the first embodiment of the present invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, Fig. 3 is a sectional view taken along B-B in Fig. 2, and Fig. 4 is Fig. 3. 5 is a sectional view taken along line D-D of the main part of FIG. 3, FIG. 6 is a sectional view taken along line E-E of FIG. 3,
FIG. 7 is a sectional view showing a second embodiment of the present invention, FIG. 8 is a view showing an example of application of the present invention to a fuel injection pump, and FIGS. 9 and 10 are views of a conventional distributed radial plunger pump. Figures 11 to 14 are diagrams for explaining the problems of conventional distributed radial plunger pumps; Figures 1 to 22 The figure is a sectional view for explaining the switching operation of the bottle valve and the distribution disk in the first embodiment of the present invention. 8...Rotor. 10a-10d...Plunger, 1
7...Cam ring, 22...Distribution disk. 23・
...pintle valve. 23a... common discharge passage, 24
a...Distribution discharge passage, 27...Rear housing, 2
8...Front housing, 32a...Discharge port, 3
3a to 33d...Cylinder. 2nd Reh 4th Figure 3 Figure 3 Figure Fue et et al.

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, the pump comprising: a discharge port provided in the housing for discharging working fluid; and a rotation center of the rotor. a discharge passage fixed to the housing in a slidable manner with respect to the rotor and communicating with the cylinder hole at a predetermined position; and a plurality of distribution passages communicating with the common discharge passage and corresponding to the number of the cylinder holes. a pintle valve having a discharge passage therein; and a distribution disk that rotates integrally with the rotor and has an opening that slides on the pintle valve and communicates the distribution discharge passage and the discharge port at a predetermined position. A radial plunger pump comprising: