JPS636760B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oil pump that includes two sets of pumps and a pair of spool valves that selectively supply pressurized fluid from both pumps to fluid equipment.

For example, in a power steering system installed in a car that reduces the driver's steering effort, the pump used as the source of hydraulic pressure is usually rotated by the car's engine, and its discharge volume is proportional to the engine's rotation speed. increase or decrease. Therefore, such a pump must have a capacity that can supply a sufficient flow rate without interfering with the operation of fluid equipment such as the power snake control device even when the engine speed is low, that is, when the pump discharge amount is small. is required. However, if such a capacity is set, an unnecessarily large flow rate will be supplied in the high rotation range of the engine, which is not only wasteful, but also increases the horsepower consumption of the engine to drive this pump.
It greatly affects the fuel efficiency of automobile engines and is not desirable from the viewpoint of energy saving measures.

For this reason, conventionally, by combining two small-capacity pumps with a control unit that selectively supplies pressurized fluid from both pumps to fluid equipment, only one pump is always supplied with hydraulic pressure. The other pump is connected to the tank side and left in an unloaded state to reduce horsepower consumption, and the control section is activated only when necessary to combine and supply pressure fluid from both pumps. It is considered. One way to control the amount of pressure fluid supplied is, for example, by detecting the flow rate in the low rotation range of the engine, that is, when the pump discharge amount is small, and combining the pressure fluid from both pumps. A pressure sensing type that detects the fluid pressure that increases only when a load is applied to the fluid equipment side regardless of the engine speed, and combines the pressure fluid from both pumps. There are known systems that combine the advantages of both rotational speed and pressure sensing systems, and are selected and adopted depending on the application.

By the way, the control unit that controls the supply amount of pressure fluid mentioned above has a flow path switching function that selectively switches the flow paths from both pumps as necessary, and a function that maintains the supply amount to the fluid equipment at a predetermined amount or less. It is generally considered that these functions are performed using a pair of spool valves and a pressure fluid passage that combines them appropriately, but the configuration of the control section is different for each sensing type. This is a major hurdle in terms of oil pump manufacturing, assembly, and cost.

That is, the pair of spool valves and fluid passages that constitute the above-mentioned control section are normally integrated into one pump body together with the two sets of pumps, but due to the above-mentioned differences in configuration, each part, especially the pump body, is It is difficult to share the
As a result, manufacturing and assembly are performed for each sensing type, which is not suitable for mass production and raises the problem of increased manufacturing costs.

In addition, it is desirable for this type of oil pump to have a simple overall configuration, excellent ease of assembly, and to be small and lightweight. These points must also be taken into consideration, as they are large in size for devices that are installed on the device.

In view of these circumstances, the present invention has provided a pump housing provided in the center of a pump body so as to house two sets of pumps in parallel. A passage hole is formed around the space so that its axis is parallel to and close to the space, and a passage hole for guiding the pressure fluid from one of the pumps is provided between these valve holes, and the axis of this passage hole and each of the above-mentioned valves are formed. By configuring the holes so that their axes are located on approximately the same plane, it is possible to form each sensing type control section with different operating conditions by simple hole machining, which makes it possible to share the pump body. The present invention aims to provide an oil pump that can be configured to be suitable for mass production, has a simple overall configuration, is cost-effective, and also satisfies the demands for compactness and weight reduction. be.

Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

1 to 4 show an embodiment of an oil pump according to the present invention, and this embodiment shows a case where pressure sensing type flow rate control is performed.

In these figures, reference numerals 1 and 2 are a front body and a rear body that constitute a pump body, and inside thereof there are first and second pumps 3 and 4 having different discharge capacities, and discharge from both pumps 3 and 4. First and second spool valves 5 and 6 that control the supply amount of pressure oil are integrally incorporated, and a fluid passageway is formed to appropriately connect them.

That is, as shown in FIGS. 2 and 3, a bottomed pump storage space 7 is formed in the center of the rear body 2 and opens toward the front body 1. First and second pumps 3, 4 are arranged side by side in the axial direction. These pumps 3 and 4 are rotationally driven by a common drive shaft 8 inserted through the central hole 1a of the front body 1, and perform pumping operations respectively.

Note that these first and second pumps 3 and 4 have a conventionally well-known vane pump configuration, and to briefly explain this, the first pump 3 is connected to the drive shaft 8.
The pump includes a rotor 9 having a plurality of vanes 9a fixed thereon, a cam ring 10, a side plate 11, a pressure plate 12, etc., and is disposed within a large diameter portion 7a formed on the opening side of the pump storage space 7. Ru. In this case, the side plate 11
is locked by a step 7b provided in the axial center of the storage space 7, and is connected to a second pump 4, which will be described later.
It also serves as a side plate. Further, the pressure plate 12 is disposed on the opening side of the storage space 7, and forms a pressure chamber 13 on the pump discharge side between it and the front body 1 that closes this opening.

On the other hand, the second pump 4 is also fixed on the drive shaft 8 and includes a rotor 14 having a plurality of vanes 14a, a cam ring 15, a pressure plate 16, etc., and the storage space 7 is formed on the bottom side. It is disposed within the small diameter portion 7c.

A spring 17 is disposed between the pressure plate 16 and the bottom of the storage space 7, and this part serves as the pressure chamber 1 on the discharge side of the second pump 4.
8. Although a spring 19 is also provided in the discharge side pressure chamber 13 of the first pump 3, these springs 17 and 19 are not necessarily necessary. In addition, the cam rings 10 of both pumps 3 and 4,
15 has pressure chambers 20, 21 on the pump suction side.
These pressure chambers 20 and 21 communicate with each other through a hole 22 formed in the side plate 11. These suction side pressure chambers 20,
Hydraulic oil from an oil tank (not shown) is led to 21 through an inlet passage 23 formed on the side of the rear body 2 and a passage 24 communicating with a valve hole of one of the spool valves, which will be described later. Furthermore, in the figure, 25 is a rod for positioning each of the above-mentioned pump components, 26 is a bearing that pivotally supports the drive shaft 8 within the front body 1, and 27 is an oil seal that prevents oil leakage to the outside.

In this case, according to the configuration described above, if the capacity of the first pump 3 is set smaller than that of the second pump 4, the energy saving effect can be further improved. Furthermore, it is desirable to arrange the components of both pumps 3 and 4 in parallel with different phases in the rotational direction, and to shift the phase of the pulsation of the discharge pressure from each pump so that smooth pumping action can be obtained. .

Further, the rear body 2 is connected to the pressure oil discharged from the first and second pumps 3 and 4 through an outlet passage 30 that opens to the side of the rear end of the rear body 2 to supply fluid to a power steering device or the like. A control section consisting of a pair of spool valves 5, 6 and a fluid passage for selectively supplying equipment to the equipment is appropriately arranged around the pump storage space 7.

That is, in the figure, reference numerals 31 and 32 indicate a pair of valve holes arranged in parallel on the upper side of the rear body 2 so as to be close to each other. It opens at the joint surface on the body 1 side and is formed so that the axial direction is parallel to the pump storage space 7. These valve holes 31 and 32 are closed together with the pump storage space 7 by the front body 1 in a liquid-tight manner.

Further, reference numeral 33 denotes a passage hole bored from the rear end side of the rear body 2 so as to be located between the two valve holes 31 and 32, and the axis thereof is located between the two valve holes 31 and 32.
It is arranged so as to be located in substantially the same plane as the axis line of 32. The opening of this passage hole 33 is sealed by a blind plug 34, and is communicated with the discharge side pressure chamber 18 of the second pump 4 through a passage 35 that opens from below in the vicinity of this opening. There is. Furthermore, the other end of this passage hole 33 extends to approximately the center of the rear body 2 in the axial direction, and is connected to a passage hole 36 that is bored from the side of the rear body 2 through the one valve hole 31. ing.

Therefore, according to such a configuration, the pressure oil discharged from the second pump 4 passes through the passage 35, the passage hole 33, and the passage hole 36, and then reaches the valve hole 3.
You will be guided to the center of 1. Furthermore, 37
is a blind plug that seals the opening of this passage hole 36.

On the other hand, a common passage hole 38 is arranged on the side of the rear body 2 and is bored from the rear end side of the rear body 2 in parallel with the pump storage space 7, and a part of the common passage hole 38 opens into the outlet passage 30. ing. Furthermore, 39
is a ball that closes the opening of the common passage hole 38.

The pump storage space 7, the pair of valve holes 31 and 32, and the common passage hole 38 correspond to the discharge side pressure chamber 13 of the first pump 3 formed near the opening of the pump storage space 7. A rectangular passage groove 4 formed in the rear body 2 as shown in FIG.
0, 41; and 42, respectively. Moreover, in the first valve hole 31,
Passage hole 3 through which pressure oil from the second valve 4 is guided
A return passage groove 43 communicating with the pump storage space 7 is formed at a position corresponding to the suction side pressure chamber 21 of the second pump 4 on the rear end side of the pump 6 .
On the other hand, on the second valve hole 32 side, a passage 24 that communicates with the input passage 23 from the side of the rear body 2 described above opens so as to be located on the front end side of the central part in the axial direction. 24 is the second
As shown in the figure, it is connected to the pump storage space 7 at a position corresponding to the suction side pressure chamber 20 of the first pump 1. Note that the small hole portion formed between the common passage hole 38 and the passage groove 42 is an orifice for detecting the supply flow rate to the fluid equipment and operating the spool valve 6 which becomes a flow rate control valve to be described later. 4
It is 4.

In such a configuration, the valve hole 31,
Spools 45 and 46, which constitute first and second spool valves 5 and 6, which operate as a flow path switching valve and a flow rate control valve, respectively, are incorporated in 32.

That is, the spool 45 installed in the first valve hole 31 is always located at the front end on the front body 1 side due to the spring 47 installed in the bottom side of the valve hole 31. In this state, the annular groove 45a formed on the rear end side of the spool 45 communicates with the passage hole 36 and the return passage groove 43, so that the pressure oil from the second pump 4 is pump-suctioned. Reflux to the side. Also,
A check valve 48 is disposed at the front end of the spool 45, and when the spool 45 moves toward the rear end, the check valve 48 passes through the through hole 45b and the annular groove 45c on its outer periphery. It is connected to the passage holes 33 and 36 from the pump 4 of No. 2. Of course, during this operation, the passage hole 36 and the return passage groove 43 are separated by the land portion 45d of the spool 45.
Then, the check valve 48 is opened by the pressure oil from the second pump 4, and the pressure oil flows into the discharge side pressure chamber 13 of the first pump 3 via the passage groove 40 that opens to the front end of the valve hole 30. It plays a role of guiding and merging the discharge pressure oil of the first pump 3. In the first spool valve 5 having the above-described configuration, the hydraulic pressure on the discharge side pressure chamber 13 side of the first pump 3 is supplied to the high pressure chamber 49 formed at the front end of the spool 45 via the passage groove 40. Further, hydraulic pressure on the suction side is led to the low pressure chamber 50 on the rear end side through a small hole 45e. The spool 45 is connected to the discharge side pressure chamber 13, the passage groove 42, the common passage hole 38 having the orifice 44, etc., and the fluid pressure in the main supply passage increases due to an increase in the load on the fluid equipment side. A pressure-sensing flow path switching valve is configured that senses this and operates to switch the flow path only when the pressure is detected.

Further, the spool 46 incorporated into the second valve hole 32 constitutes a conventionally known flow control valve. That is, the hydraulic pressure on the discharge side pressure chamber 13 side, that is, on the upstream side of the flow rate detection orifice 44 is introduced into the high pressure chamber 51 formed at the front end of the valve hole 32 by the spool 46 via the passage groove 41. On the other hand, hydraulic pressure downstream of the orifice 44 is guided to a low pressure chamber 52 on the rear end side through a passage 53 communicating with the outlet passage 30. The spool 46 is normally positioned on the front end side of the valve hole 32 by a spring 54 disposed in the low pressure chamber 52, and at this time, an annular groove 46a provided on the outer periphery of the central portion thereof is continuous with the inlet passage 23. The discharge side pressure chamber 13 and the passage 24 are separated from each other. On the other hand, when the flow rate of the pressure oil sent out from the discharge side pressure chamber 13 increases and exceeds a predetermined amount, the spool 46 is moved to the valve hole 3 due to the differential pressure generated above the orifice 44 and on the downstream side.
2, connects the discharge side pressure chamber 13 and the passage 24 as appropriate, and returns a predetermined amount or more of pressure oil to the pump suction side.

Note that the passage 53 communicating the outlet passage 30 and the low pressure chamber 52 is formed by a hole bored from the outside of the body forming the outlet passage 30, as shown in FIG. It is constructed so that it can be easily processed. In this case, 53a in the figure is an orifice for preventing oscillation of the spool 46, and 53b is a ball that seals the opening of the passage 53. Furthermore, a well-known relief valve 55 is attached within the spool 46.

Further, on both sides of the front body 1, fourth
As is clear from the figure, a pair of mounting brackets 56a and 56b are provided protrudingly, and the front body 1 and rear body 2 are integrally connected by four bolts 57. In addition, the reference numeral 58 in FIG. 4 is an outlet member for connection to the fluid equipment side;
Reference numeral 9 denotes an inlet member connected to the oil tank side, which is attached to the outside of the rear body 2 in correspondence with the aforementioned outlet passage 30 and inlet passage 23, respectively.

According to the oil pump equipped with the control section having such a configuration, only the pressure oil from the first pump 3 is normally transferred from the pressure chamber 13 on the discharge side to the common passage having the passage groove 42 and the orifice 44. hole 38,
It is connected to fluid equipment such as a power steering device through the outlet passage 30. On the other hand, the pressure oil from the second pump 4 flows from the pressure chamber 18 on the discharge side to the passage 35 and the passage hole 3.
3 and 36 into the first valve hole 31, but since the spool 45 is inactive, it returns to the pump suction side via the return passage groove 43 and circulates therebetween. Therefore, in such a state, the second pump 4 is kept in an unloaded state, thereby reducing the horsepower consumption for driving the pump.

Further, when a load is applied to the fluid equipment side and the fluid pressure in the pressure chamber 13 on the discharge side as the main supply passage increases, the spool 45 moves to the right in FIG. 1 within the first valve hole 31. And this first
The spool valve 5 becomes activated. Then,
A passage hole 33 that guides pressure oil from the second pump 4,
36 is separated from the return passage groove 43 and further connected to the check valve 48 via the annular groove 45c and the through groove 45b. Then, due to the pressure difference, the check valve 48
is opened, and as a result, the pressure oil from the second pump 4 joins with the pressure oil from the first pump 3 in the discharge side pressure chamber 13 of the first pump 3 via the passage groove 40. It is supplied from the discharge side pressure chamber 13 to the fluid equipment side via the passage groove 42, the common passage hole 38, and the outlet passage 30, ensuring the amount of supply necessary for its operation.

On the other hand, when the flow rate of the pressure oil from the first pump 3 or the combined pressure oil from the first and second pumps 3 and 4 exceeds a predetermined amount, the spool 46 is moved to the right side in FIG. 1 due to the differential pressure generated above and downstream of the orifice 44, and as a result, the excess flow is returned to the tank side.
As a result, the supply amount of pressure oil is maintained at a predetermined amount.

In the oil pump configured as described above, the pair of spool valves 5 and 6, which operate as flow path switching valves and flow rate control valves, have their axes aligned around the pump storage space 7 formed at the center of the pump body. The valve holes 31 and 32 are arranged in parallel and close to each other, and the pump storage space 7 is connected to the valve holes 31 and 32.
The passage that connects the pump body and the passage that connects to the fluid outlet and inlet are constructed of cast holes that are formed integrally with the pump body and drilled holes that are formed by simple hole machining, making the entire structure simple and compact. It has the advantage that it has a simple pump configuration, is easy to manufacture and assemble, and is inexpensive to manufacture.

In particular, as shown in the embodiment described above, the pump storage space 7 and the pair of valve holes 31, 32 are opened at the joint surface of the divided rear body 2 on the front body 1 side, and each pump is opened from this opening side. Since it is configured to incorporate valve component parts such as component parts, spools, and springs, it is excellent in terms of ease of assembly, and is also advantageous in terms of sealing performance of each opening.

Further, the opening sides of the respective valve holes 31 and 32 are defined as high pressure chambers 49 and 51, passage grooves 40 and 41 are formed therein, and a discharge side pressure chamber of the first pump 3 is formed on the side of the pump housing space 7. 13, and further communicates this pressure chamber 13 with the common passage hole 38 side on the output side via the passage groove 42, whereby the discharge side pressure chamber 13 of the first pump 3 is connected to the second pump 3. Since it is used as the main supply passage including the merging section where the pressure oil from 4 is merged, the pump structure is simpler and it is advantageous in terms of manufacturing.

Now, according to the present invention, by making a simple hole in the pump body of the oil pump having the above-mentioned simple configuration and appropriately changing the shape of the spool according to the request, the control unit with completely different operating conditions can be used. It can be said that the oil pump structure has excellent versatility.

That is, FIGS. 5 to 7 show an embodiment of an oil pump that is equipped with a control unit that senses both pressure and rotational speed. The difference is that a passage hole 36 is provided from the side of the rear body 2 to connect one valve hole 31 with a passage hole 33 formed between a pair of valve holes 31 and 32. , it is formed so as to penetrate to the other valve hole 32. This through passage is indicated by the reference numeral 60 in the figure, and is connected to the pair of valve holes 3.
This is clear from the fact that the axes of the holes 1 and 32 and the axis of the passage hole 36 are located on substantially the same plane. The configuration of each other part is the same as that of the oil pump shown in FIGS. 1 to 4, so the same reference numerals are given and detailed explanation thereof will be omitted.

According to such a configuration, when the pump driving rotation speed increases and the discharge amount from the first pump 3 exceeds a predetermined amount, the second spool valve 6, which functions as a flow rate control valve, becomes a flow path switching valve. It also operates as a pump, and the pressure oil from the second pump 4 is connected to the tank side, thereby making it possible to increase the energy saving effect. That is, when the second spool valve 6 operates, the through passage 60, which is normally closed by the land portion 61 of the spool 46, opens into the annular groove 4.
It is connected to the tank side passage 24 via 6a.
In this state, even if the first spool valve 5 is activated due to an increase in the load on the fluid equipment side and the passage holes 33 and 36 communicate with the check valve 48 side, the check valve 48 will not be opened. Second
The pressure oil from the first pump 4 is returned to the tank side without merging with the pressure oil from the first pump 3. Therefore, the second pump 4 is kept in an unloaded state, and its horsepower consumption is reduced.

Furthermore, FIGS. 8 to 10 show an embodiment of an oil pump equipped with a rotation speed sensing type control section, and most of the oil pumps are of the pressure sensing type shown in FIGS. 1 to 4. They have the same configuration and are given the same numbers, but the differences are as follows.

That is, in the oil pump in this embodiment, as is clear from FIGS. 8 and 10,
Above the passage hole 33 formed between the pair of valve holes 31 and 32, a small diameter passage hole 70 is bored from the rear end of the rear body 2 with the axis parallel to the passage hole 33, and the opening of this small diameter passage hole 70 The part side is rear body 2
A small hole 71 formed diagonally from the top end communicates with the first valve hole 31, while a small hole 72 formed diagonally from the top end of the rear body 2 communicates with the second valve hole 31 on the bottom side. It communicates with the hole 32. Of course, the small diameter passage hole 70 and the pair of small holes 7
1, 72 openings are balls 70a; 71a, 72
It is sealed by a. And the first valve hole 3
The spool 73 incorporated in the spool 73 connects the check valve 48 with the passage holes 33 and 36 that guide the pressure oil from the second pump 4 through an annular groove 73a and a through groove 73b on its outer periphery, and a return passage groove. 43 with its land portion 73c, and thereby the first
The spool valve 5 functions as a rotation speed sensing type flow path switching valve. The small hole 71 opens into the low pressure chamber 50 on the right side of the spool 73.

On the other hand, in the spool 74 incorporated in the second valve hole 32, the land portion 74a forming the low pressure chamber 52 normally opens the small hole 72 to the low pressure chamber 52 side, and during operation. Small hole 72
It is configured to pass over the opening of the tank and communicate with the passage 24 on the tank side via the annular groove 74b.

According to such a configuration, when the rotation speed is small and the discharge amount from each pump 3, 4 is small, the pressure oil from the second pump 4 opens the check valve 48 and flows to the first pump 3. It is supplied by combining with pressure oil from. Further, when the combined supply amount exceeds a predetermined amount, the second spool valve 6, which functions as a normal flow rate control valve, is activated and returns the excess flow to the tank, while the land portion 74a of the spool 74 is activated. The small diameter 72 is switched from pump discharge pressure to tank pressure. Then, the first spool valve 5 moves to the right, and the annular groove 73a,
The through groove 73b is connected to the return passage groove 43, and the second
Pressure oil from the pump 4 is separated from the main supply passage side and returned to the tank side via the return passage groove 43.
In other words, in the high rotation range of the pump where the supply amount is guaranteed only by the discharge amount from the first pump 3, the second pump 4 is disconnected and placed in an unloaded state, thereby operating to reduce the horsepower consumption. .

As explained above, according to the oil pump according to the present invention, a pair of valve holes are provided around the pump storage space for storing two sets of pumps, the axes of which are parallel to the space and close to each other, and a pair of valve holes are provided between the two valve holes. Since the axes of the passage hole formed in the pump and the passage hole through which the pressure fluid from one pump is guided are located in the same plane, flow rate control with completely different operating conditions can be performed by simple hole machining, etc. This makes it possible to share the pump body and create a configuration suitable for mass production.Moreover, the overall configuration is simple and the manufacturing cost is low, and it also satisfies the requirements for smaller diameter and lighter weight. There are various excellent effects such as being able to. In addition, the pump body is divided into two parts, and the pump storage space and a pair of valve holes are opened on one joint surface, and the other body is configured to close this, thereby making it easier to assemble each member. It has the advantage that it can be easily and reliably sealed, and that each opening can be reliably sealed all at once.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment in which the present invention is applied to a pressure-sensing oil pump, FIG. 2 is a vertical cross-sectional view of the same, and FIG.
4 is a side view, FIG. 5 is a cross-sectional view showing another embodiment in which the present invention is applied to a pressure/rotational speed sensing type oil pump, and FIG. 6 is a longitudinal sectional view, and FIG. 7 is a cross-sectional view taken along the line 5 and 6, FIG. 8 is a cross-sectional view showing another embodiment in which the present invention is applied to a rotation speed sensing type oil pump, and FIG. 9 is a vertical cross-sectional view as well. Figure 10 is similar to Figures 8 and 9.
It is a sectional view taken along the line - in the figure. 1...Front body, 2...Rear body, 3
...First pump, 4...Second pump, 5...
First spool valve, 6...Second spool valve, 7...Pump storage space, 8...Pump drive shaft, 30...Outlet passage, 31...First valve hole, 32...Second spool valve Valve hole, 33...passage hole.

Claims (1)

[Claims] 1. Two sets of pumps that separately discharge pressure fluid, and a pair of spool valves that switch the flow paths of the pressure fluid from these two pumps and control the amount of supply to fluid equipment are integrated. In the oil pump, the pump body includes a pump housing space in which the two sets of pumps are arranged side by side on a common drive shaft, and an axial direction of the pump housing space. The valve holes of the pair of spool valves are formed close to each other around the pump storage space so as to be parallel to each other, and the passage hole is located between these valve holes and through which the pressure fluid from one of the pumps is guided. An oil pump characterized in that the pair of valve holes and the axis of the passage hole are located in substantially the same plane. 2. A pump body that integrally incorporates two sets of pumps that discharge pressure fluid separately, and a pair of spool valves that switch the flow paths of pressure fluid from these two pumps and control the amount of supply to fluid equipment. In the oil pump, the pump body is divided into a front body and a rear body, and the rear body includes:
a pump storage space in which the two sets of pumps are arranged side by side on a common drive shaft; and a pump storage space formed adjacent to each other around the pump storage space so that the axial direction is parallel to the pump storage space. An oil pump characterized in that the valve holes of the pair of spool valves are formed to open on the joint surface side so as to be closed by the front body.