JPS61222857A - Power steering pump provided with vacuum pump - Google Patents

Abstract

PURPOSE:To make it possible to stably supply lubrication oil into a vacuum pump, by using hydraulic oil in a power steering device as the lubrication oil of the vacuum pump. CONSTITUTION:Hydraulic oil fed from the outside flows into a power steering pump through a suction port 26, then into a hydraulic chamber 35 in a control valve 4 through a discharge port formed in a side plate 23 after being pressurized, and is discharged from a hydraulic oil discharge port 36. A part of hydraulic oil which is pressurized by a PS pump 3 flows into a high pressure chamber 29, and thereafter, flows into a low pressure chamber 37, after depressing a spool 28 in a relief valve 5. A part of hydraulic oil having flown into the low pressure chamber 37 is again sucked into the PS pump 3 through its suction port 27, and the remaining part of the hydraulic oil is fed into a pump cavity 43 in a vacuum pump 2 through an oil passage 47 formed in a common side plate 14, and severs as lubrication oil in a vacuum pump 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power steering pump used in a steering system equipped with an eccentric vacuum pump used in a brake booster for an automobile.

[Conventional technology]

Conventionally, a vacuum pump used in a brake booster and a power steering pump used in a steering system have been constructed separately and installed in an automobile as completely separate systems.

The vacuum pump was attached to the generator and used engine oil as lubricant. For this reason, piping for oil supply from the engine side and piping for return oil from the vacuum pump are required, resulting in a very complicated engine layout. Since this depends on the system and piping route, there is a problem in that the oil pressure supplied to the vacuum pump varies depending on the vehicle model to which it is applied, making it impossible to obtain a stable supply of lubricating oil. In addition, since engine oil is used directly as the lubricating oil for the vacuum pump, sludge in the engine oil,
Carbon powder, etc. may cause abnormal wear on the sliding parts, sealing rubber parts, or spline drive parts in the vacuum pump, causing deterioration of the valve head of the vacuum pump, and in the unlikely event that oil leaks on the vacuum pump side. There is a problem in that if a problem such as leakage occurs, there is a risk of causing great damage to the engine side.

[Problem that the invention seeks to solve]

The present invention has been made to solve the above problems, and it is possible to use power steering hydraulic oil as a lubricating oil for a vacuum pump without using engine oil, and to ensure a stable supply of lubricating oil. The purpose of the present invention is to provide a puff steering pump with a vacuum pump that can be used.

[Means for solving problems]

Generally, the steering force in an actual vehicle is required at low speeds rather than at high speeds, so the hydraulic oil flow rate of the puff steering pump is used mostly at low speeds and only a little at high speeds. Conversely, it is necessary to circulate a large amount of lubricating oil for cooling at high speeds.

The present invention focuses on the above-mentioned difference in hydraulic oil flow rate characteristics. In order to achieve the above object, the present invention includes a rotating shaft;
A vacuum pump driven by this rotary shaft, a puff steering pump consisting of a vane pump driven by the same rotary shaft, and a control valve provided in the housing of the puff steering pump to throttle the discharge flow according to the oil pressure at the discharge port of the vane pump. A flow control valve consisting of a relief valve that returns hydraulic oil at the discharge port to a low pressure side according to the oil pressure at the discharge port of the vane pump, and an oil passage that guides a portion of the returned oil from the relief valve to the vacuum pump. A power steering pump with a vacuum and pump featuring the following is provided.

[Effect]

According to the configuration of the present invention, the hydraulic oil of the power steering pump is supplied to the vacuum pump via the oil passage and is used as lubricating oil for the vacuum pump. In addition, when the rotating shaft rotates at high speed, the discharge pressure of the vane pump increases and the discharge flow from the control valve is throttled, so the amount of oil returned from the I-no-7 valve increases and the amount of oil supplied to the vacuum pump increases. Therefore, it is possible to stably supply the amount of lubricating oil required by the vacuum pump.

〔Example〕

An embodiment of the present invention will be specifically described with reference to the drawings. FIG. 1 is a sectional view of the embodiment.

This embodiment includes a vane-type vacuum pump 2 driven by a single rotating shaft 1, a power steering pump 3 consisting of a vane pump, and a flow control valve 6 consisting of a control valve 4 and a relief valve 5 for controlling the flow rate of hydraulic oil. Equipped with

Control valve 4 and relief valve! M:1. Although they are actually constructed as a single unit, in the drawing they are shown separated into upper and lower parts for explanatory purposes.

The rotating shaft 1 is rotatably supported in the housing 7 by the bearing 8. A boot 99 is fixed to one end of the rotating shaft 1, and an oil seal 10 is provided between the boot 99 and the bearing 8. . l1li] A spline portion IA is formed on the side opposite to the pulley of the pine shaft 1, and the rotor 11 of the power steering pump 3 and the rotor 12 of the vacuum pump 2 are meshed with the spline portion IA, and a snap ring provided at the end of the shaft is formed. 1
3 to the rotating shaft 1. A common side plate 14, which also serves as a side plate for both the vacuum pump 2 and the power steering pump 3 consisting of a vane pump, connects the end surface of the housing 7 on the side opposite to the pulley and the housing 15 of the vacuum pump 2.
The housing 71 is held together with the housing 15 of the vacuum pump 2 by bolts 16. In order to make the inside of the housing 7 and V15 oil-tight,
O-rings 17 and 18 are provided between the housing 7 and the side plate 14 and between the side plate 14 and the housing 15, respectively. A cylindrical circumferential surface 19 is formed on the inner periphery of the housing 15 of the vacuum pump 2 eccentrically from the rotation center of the rotating shaft 1, and a vane 20 is radially attached to the rotor 12 so as to be in constant sliding contact with the cylindrical circumferential surface 19. It is attached so that it can slide in the direction. The housing 15 of the vacuum pump is provided with an air intake port 21 at the top facing the cylindrical circumferential surface 19 and an air discharge port 22 at the bottom. and a housing 15, a common side plate 14. ty-evening 12
and the vane 20 constitute a vacuum pump 2.

A side plate 23 serving as a side plate of the power steering pump 3 is fitted into the center of the housing 7, and a cam ring 24 is sandwiched between this side plate 23 and a common side plate 14. The cam ring 24 is provided so that its inner peripheral surface is eccentric from the center of rotation of the rotating shaft 1, and a plurality of vanes 25 are slidably mounted on the rotor 11 in the radial direction so as to be in constant sliding contact with the inner peripheral surface. The side plate 23 is provided with two hydraulic fluid inlets 26, 27 and two discharge ports (not shown) at positions symmetrical to the axis of the rotating shaft 1. And side plate 23.
Common side plate 14. Cam ring 24. Rotor 1
The power steering pump 3 is composed of a vane pump that pressurizes hydraulic oil using vanes 1 and 25. A high pressure chamber 29 is provided in the housing 7 in communication with a discharge port (not shown) provided in the side plate 23, and facing the high pressure chamber 29 are the control valves 4 and +)').
-7/A flow control valve 6 consisting of a valve 5 is provided.

A cylindrical control valve main body 30 is oil-tightly screwed into the housing 7, and a cylindrical member 31 is fixed within the control valve main body 30. *A plurality of small holes are formed in the center and around the bottom of the component 31 to form an orifice 32.

Below the orifice 32, a control valve body 33 is slidably inserted into the control valve body 30, and is biased away from the orifice 32 by a spring 34. The oil chamber below the control spool 33 is pressure chamber 2
9, and when the oil pressure in the high pressure chamber 29 increases, the control spool 33 is moved upward to close the small hole in the center of the orifice 32, thereby restricting the flow rate of hydraulic oil passing through the orifice 32. The oil chamber 35 upstream of the orifice 32, that is, between the control spool 33 and the orifice 32, communicates with a discharge port (not shown) of the power steering pump 3, and downstream of the orifice 32 is a hydraulic oil discharge port to which piping to the steering gear box is connected. It is connected to 36. Then, the control valve body 30. Orifice 3
2. A cylindrical member 31. The control spool 33 and the spring 34 form the control valve 4 at Vt.

A relief valve 5 is provided integrally with this control valve 4. In FIG. 1, for illustrative purposes, the housing 7 is drawn as if it were a separate body below it.

The relief valve 5 is a well-known balance piston carved leaf valve that limits the maximum pressure of the high pressure chamber 29 and returns the hydraulic oil in the high pressure chamber 29 to the low pressure chamber 37 communicating with the suction port 27, and has a relief spool 38tU facing the high pressure chamber 29. ') - "y Spring 39 for biasing the spool Plunger 40, which is a pilot pulp, is inserted into the inside of the relief spool 38.
Ball 41. It is composed of a seat 42 and a setting spring 43.

The oil chamber 44 upstream of the seat 42 communicates with the oil chamber 35 of the control valve 4, and the oil chamber 45 downstream of the seat 42 communicates with the low pressure chamber 3.
It is connected to 7. When the oil pressure in the oil chamber 44 increases, the ball 41 is pushed, the seat 42 opens, and the hydraulic oil in the oil chamber 44 flows out, causing the oil pressure balance on the left and right sides of the relief spool 38 to collapse, causing the relief spool 38 to move to the right. The hydraulic oil in the high pressure chamber 29 is returned to the low pressure chamber 37. The control valve 4 and relief valve 5 described above constitute a flow control valve 6.

Here, an oil passage 47 that communicates the pump chamber 46 of the vacuum pump 2 and the low pressure chamber 37 is provided in the common side plate 14.
is provided, and the low pressure chamber 37 is opened by the relief valve 5.
A part of the hydraulic oil returned to is supplied to the vacuum pump 2.

Power steering pump 101 with vacuum pump described above
We will explain the flow of hydraulic oil inside.

Hydraulic oil supplied from the outside enters the power steering pump from the suction port 26, is pressurized, and passes through the side plate 2.
The hydraulic fluid flows into the oil chamber 35 in the control valve 4 from a discharge port (not shown) provided in the hydraulic fluid 3, and is discharged from the hydraulic fluid discharge port 36 after its flow rate is restricted by the orifice 32. On the other hand, a part of the hydraulic oil pressurized by the power steering pump 3 flows into the high pressure chamber 29 and the relief spool 3 of the relief valve 5
8 to the right in the drawing and flows into the low pressure chamber 37.

A part of the hydraulic oil that has flowed into the low pressure chamber 37 is sucked into the power steering pump 3 again from the suction port 27, and the rest is supplied to the pump chamber 46 of the vacuum pump 2 from an oil passage 47 provided in the common side plate 14. Ru. The hydraulic oil supplied into the pump chamber 46 acts as a lubricating oil for the vacuum pump 2,
It is discharged from the discharge port 22 together with air.

FIG. 2 is a hydraulic oil circuit diagram when the vacuum pump-equipped power steering pump 101 of this embodiment is mounted on an actual vehicle, and FIG. 3 is a hydraulic oil flow characteristic diagram.

Hydraulic oil supplied from the reserve oil tank 102 flows into the power steering pump 3, is pressurized, and is led to the flow control valve 6.

The flow control valve 6 controls the flow rate,
As shown in FIG. 3, a relatively large amount of pressurized hydraulic fluid is sent to the steering gear box 103 of the power steering device during low speed rotation, and a relatively small amount during high speed rotation. The pressurized hydraulic oil is used as steering power by the steering gear box 103 and is returned to the reserve oil tank 102. As a result of the flow rate control by the control valve 6, a part of the pressurized hydraulic oil that is not discharged to the steering gear box 103 is supplied to the vacuum pump 2 via the oil passage 47, and the rest is supplied to the power steering pump 3. returned to the suction side. The hydraulic oil supplied to the vacuum pump 2 acts as lubricating oil, is discharged from the vacuum pump 2, and returns to the reserve oil tank 102 via the filter 104.

In this way, during low speed rotation, a relatively large amount of hydraulic oil is supplied to the steering gear box 103 and contributes to the steering force, and a relatively small amount of hydraulic oil is supplied to the vacuum pump 2 as lubricating oil. On the other hand, during high speed rotation, a relatively small amount of hydraulic oil is supplied to the steering gear box 103, and a relatively large amount of hydraulic oil is returned and supplied to the vacuum pump 2 to provide sufficient lubrication and cooling.

〔Effect of the invention〕

As explained above, the present invention integrates a vacuum pump used in a brake booster and a power steering pump used in a steering system, and uses the hydraulic oil returned in the power steering pump as a lubricating oil for the vacuum pump. Since it is used in a vacuum pump, there is no need for engine oil piping from the engine to the vacuum pump, and it is possible to efficiently use hydraulic oil, which makes it easy to install on an actual vehicle. A stable supply of lubricating oil to the vacuum pump is possible regardless of the vehicle type. Furthermore, since it does not use vacuum oil, it has excellent effects such as extending the life of the vacuum pump.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the embodiment, FIG. 2 is a hydraulic fluid circuit diagram when the embodiment is mounted on an actual vehicle, and FIG. 1143 is a hydraulic fluid flow characteristic diagram. 1...Return pump, 2...Vacuum pump, 3...Power steering pump consisting of vane pump, 4...Control valve, 5...17 +7-7 valve, 6
70-control valve, 7-housing, 14-side plate, 15-housing,
23... Side plate, 26.27... Inlet,
29... High pressure chamber communicating with the discharge port, 32... Orifice, 33... Control spool, 47... Oil passage. Figure 2 6; Flofuntrol pulp Figure 3 Rotational speed (RPM)

Claims (1)

[Claims] A rotating shaft, a vacuum pump driven by the rotating shaft,
A power steering pump consisting of a vane pump driven by the same rotating shaft, a control valve provided in the housing of the power steering pump that throttles the discharge flow according to the oil pressure of the discharge port of the vane pump, and a control valve that throttles the discharge flow according to the oil pressure of the discharge port of the vane pump. A power steering pump with a vacuum pump, comprising: a flow control valve consisting of a relief valve that returns hydraulic oil to a low pressure side; and an oil passage that guides a portion of the oil returned from the relief valve to the vacuum pump.