JP2544107Y2 - Pump device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump device used, for example, in a power steering device of an automobile.

[0002]

2. Description of the Related Art Generally, a vane pump or a gear pump is used as a hydraulic pump for a power steering device of an automobile, and these hydraulic pumps are connected to a crankshaft of an engine by a pulley and a belt and driven. Since the power steering device requires almost no oil pressure during normal running of the vehicle, most of the oil discharged from the hydraulic pump is returned to the reservoir through the hydraulic circuit of the power steering device.

[0003]

In recent years, the hydraulic circuit of the power steering device has tended to be complicated as a countermeasure against pulsation of the hydraulic pump, and the capacity of the hydraulic pump has increased with the size of the vehicle. Even when the power steering device is not operating, the oil passing through the hydraulic circuit receives a large oil flow resistance, which not only causes an increase in horsepower consumption of the hydraulic pump and deterioration of fuel efficiency, but also causes vibration and noise. .

The present invention has been made in view of the above circumstances, and has as its object to reduce the horsepower consumed by a hydraulic pump when an actuator does not operate.

[0005]

In order to achieve the above object, the present invention provides a pump device for supplying discharge oil of a hydraulic pump driven by a prime mover to an actuator via an oil passage. The rotation shaft of the actuator is connected via a clutch that is engaged according to a change in the pressure of the oil passage accompanying the operation of the actuator.
When the pressure in the oil passage decreases, the clutch
Together with the oil
The clutch is fully engaged when the road pressure increases .

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

1 to 3 show one embodiment of the present invention. FIG. 1 is a hydraulic circuit diagram of a power steering device, and FIG.
2 is a sectional view taken along line 2-2 of FIG. 1, and FIG. 3 is a sectional view taken along line 3-3 of FIG.

As shown in FIG. 1, a hydraulic pump P composed of a balanced vane pump is connected to a crankshaft of an engine E by a pulley and a belt, and feeds oil sucked up from a reservoir R through a suction oil passage 1 to feed oil. The oil is supplied to the power steering device A as an actuator via the passage 2, and the return oil from the power steering device A is returned to the reservoir R via the return oil passage 3.

The power steering apparatus A is a well-known vehicle speed sensitive type, and has a power cylinder 4 for assisting a steering force.
A 4-way valve 5 for selectively communicating a pair of working chambers 4 ₁ , 4 ₂ of the power cylinder 4 with the hydraulic pump P and the reservoir R; a rack 7 ₁ , a pinion 7 linked with the rotation of the steering wheel 6 _2, and comprises a valve actuating mechanism 7 is composed of a pinion holder 7 ₃ switching the 4-way valve 5.

[0010] Power steering device A, so as to generate the steering reaction force corresponding to the vehicle speed to regulate the movement of the 4-way valve 5, a pair of recoil plunger ₈₂ biased by a spring 8 ₁ at both ends A plurality of reaction chambers 8, a cut-off valve 9 for controlling communication and shutoff between the hydraulic pump P and the reaction chamber 8, a trochoid motor 10 ₁ rotating at a speed proportional to the vehicle speed, a one-way valve 10 ₂ , and a relief valve 10 _Three
And a vehicle speed sensor 10 for controlling the operation of the cutoff valve 9.

As shown in FIGS. 2 and 3, the hydraulic pump P
The ball bearing 1 is located at the front of the pump housing 11.
A pump input shaft 14 is rotatably supported via a seal 2 and a seal 13, and a pulley 15 receiving a driving force of the engine E is mounted on a protruding portion of the pump input shaft 14 from the pump housing 11. A cam ring 16 having an elliptical inner peripheral surface and a circular rotor 18 serrated and coupled to a pump rotating shaft 17 coaxial with the pump input shaft 14 are housed in a rear portion of the pump housing 11.
A plurality of vanes 19 slidably supported by slits formed in the radial direction on the outer periphery of 8 come into contact with the inner peripheral surface of the cam ring 16. A front side plate 2 for rotatably supporting a pump rotating shaft 17 is provided on front and rear surfaces of a cam ring 16 and a rotor 18.
0 and a rear side plate 21 are arranged, and a plurality of working chambers are formed by the side plates 20 and 21, the cam ring 16, the rotor 18, and the vane 19. A pair of suction ports 22 and a discharge port 23 are formed on both side plates 20 and 21, respectively.
The oil sucked into the working chamber whose volume is increased from the suction port 22 with the rotation of 8 is discharged to the discharge port 23 from the working chamber whose volume is reduced.

The rear side plate 21 is slidably supported in the pump housing 11 in the axial direction.
An oil chamber 25 formed between the feed oil passage 2 and the back plate 24 covering the rear part of the feed oil passage 2 is connected to the feed oil passage 2. The clutch 26 provided between the pump input shaft 14 and the pump rotating shaft 17 is composed of an annular clutch shoe 27 mounted on the rear end surface of the pump input shaft 14 and a friction surface 17 a formed on the front end surface of the pump rotating shaft 17. When the oil pressure acts on the oil chamber 25, the pump rotating shaft 17 is pushed forward via the rear side plate 21 and the rotor 18, and the friction surface 17a is pressed against the clutch shoe 27 to engage the clutch 26.

Next, the operation of the embodiment of the invention having the above-described configuration will be described.

When the vehicle does not operate the steering wheel 6, the four-way valve 5 connected to the steering wheel 6 via the valve operating mechanism 7 is in the neutral position, and the operating chambers 4 ₁ , 4 _{2 of the} power cylinder 4 are operated.
Is not supplied with hydraulic pressure. At this time, since the oil flow resistance of the power steering device A is relatively small, the hydraulic pressure acting on the oil chamber 25 of the hydraulic pump P from the feed oil passage 2 becomes small, and the friction surface 17a of the pump rotating shaft 17 is reduced.
And a large slip occurs between the clutch shoes 27 of the pump input shaft 14. As a result, the clutch 26 is disengaged, the driving force of the pump input shaft 14 is hardly transmitted to the pump rotating shaft 17, and the horsepower consumption of the hydraulic pump P is kept extremely low.

When the steering wheel 6 is operated in this state, the oil flow resistance of the power steering device A increases, the oil pressure in the feed oil passage 2 rises greatly, and the clutch 2
6 engage. As a result, the rotation of the pump input shaft 14 is directly transmitted to the pump rotation shaft 17, and the hydraulic pump P supplies a sufficient amount of oil to the power steering device A.

When the steering wheel 6 is operated in one direction, the four-way valve 5 is actuated via the valve actuating mechanism 7 and the operating chamber on the left side of the power cylinder 4 from the hydraulic pump P via the feed oil passage 2. 4 steering force is assisted by the hydraulic pressure is supplied to the _1. The right working chamber 4 _second oil through the return oil path 3 reservoir R
Reflux. When the steering wheel 6 is operated in the reverse direction, the working chamber 4 ₂ on the right side of the power cylinder 4
Oil is supplied, the left working chamber 4 ₁ oil flows back to the reservoir R to.

[0017] Hydraulic this time, 4 but generates a steering reaction force by reaction plunger ₈₂ housed in reaction chamber 8 by the actuation of way valve 5 is moved, the steering reaction force acting on the reaction chamber 8 Increases in size accordingly. That is, when stopped or the speed of the vehicle is small because the trochoid motor 10 ₁ of the vehicle speed sensor 10 for stopping or low speed, the oil flowing into the return oil path 3 is blocked. Therefore, the cut-off valve 9 is closed by only slightly operating the four-way valve 5, and the supply of the hydraulic pressure to the reaction chamber 8 is cut off, so that the steering reaction force is in the smallest state. This makes it possible to reduce the steering force in the case of stationary steering or the like.

[0018] As the vehicle speed increases, the rotational speed of the trochoid motor 10 ₁ of the vehicle speed sensor 10 decreases the stopping effect dam increases, the cutoff valve 9 is hardly closed gradually. As a result, the hydraulic pressure acting on the reaction chamber 8 increases, and the steering reaction force becomes larger than at the time of the stop or at the time of low-speed running.

As described above, the power steering device A
By reducing the rotation of the hydraulic pump P when it is not operating, the frictional resistance of each sliding part and the oil flow resistance are reduced, reducing the horsepower consumed by the hydraulic pump P and improving fuel economy. In addition, noise and vibration of the hydraulic pump P can be reduced.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the present invention described in the claims for utility model registration. It is possible to make design changes.

For example, in the embodiment, the hydraulic circuit of the power steering device A has been exemplified, but the present invention is applicable to a hydraulic circuit having another actuator. The hydraulic pump P is not limited to the vane pump, but may be a different type of pump such as a gear pump.

[0022]

As described above, according to the present invention, the clutch is fully engaged only when the actuator is operated and hydraulic pressure is required, and when the actuator is not operated, the clutch is not engaged .
The sliding engagement of the switch minimizes unnecessary work of the hydraulic pump when the actuator is inactive.
Suppressed, noise and vibration of the hydraulic pump is reduced with horsepower consumption resulting hydraulic pump is reduced. Also,
The control of the clutch is automatically performed according to the increase or decrease of the hydraulic pressure accompanying the operation of the actuator, so that the clutch can be reliably operated with a simple structure.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram of a power steering device.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

[Explanation of symbols]

2 ···· Feed oil passage (oil passage) 17 ··· Pump rotation shaft (rotation shaft) 26 ··· Clutch A ··· Power steering device (actuator) E ··· Motor (Engine) P ... Hydraulic pump

Claims (1)

(57) [Scope of request for utility model registration] 1. A pump device for supplying discharge oil of a hydraulic pump (P) driven by a prime mover (E) to an actuator (A) via an oil passage, wherein a rotary shaft of the prime mover and the hydraulic pump (P) is provided. 17) responds to the pressure change of the oil passage accompanying the operation of the actuator (A).
Flip connected via a clutch (26) which engages, activator
The pressure in the oil passage decreases due to the non-operation of the heater (A).
When the clutch (26) is slid and engaged,
The pressure in the oil passage increases due to the operation of the actuator (A).
A pump device , wherein the clutch (26) is fully engaged when applied .