JPH02310175A - Control valve of power steering device - Google Patents

Abstract

PURPOSE:To eliminate energy loss because of pressure oil being out of use by forming at a sleeve an oil pressure takeout port, which is put in communication with a pump port when the sleeve fitted on the spool of a control valve is in neutral position, and is blocked when the sleeve is in left-right steering position. CONSTITUTION:A sleeve 6 secured to an oil-hydraulic cylinder 8 together with a shaft end cover 7 is fitted on a spool 3 provided at its periphery with a central circumferential groove 5A, intermediate circumferential grooves 5B, 5C on the sides thereof, and end circumferential grooves 5D, 5E. Thus a control valve is formed. When the spool 3 is in the left-right steering position, a left- right steering port SL formed at the sleeve 6 is put in communication with a pump port PP, while other steering ports are in communication with a tank port M. The sleeve 6 is provided with an oil pressure takeout port Q, which is put in communication with the pump port PP when the spool 3 is in the neutral position and is blocked when in the left-right steering position. This will eliminate energy loss when the power steering is out of service.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control valve for a power steering device in a traveling vehicle such as a tractor or a construction machine.

(Prior Art) Various types of power steering devices are used in driving vehicles. For example, in the integral type shown in FIG. 3, a steering gear box 28 connects a control valve 1 and a hydraulic cylinder 8. A worm shaft 2 passing through the worm shaft 2 is interlocked with a worm shaft 2 to which a handle is attached.

The worm shaft 2 is screwed with a ball nut 1-20 through a steel ball in the hydraulic cylinder B, and this ball nut 20 meshes with the sector gear A730 of the sector shaft 29. In the control valve 1, the spool 3 and Centering plays 1, 4Δ, and 4B are fitted.

A sleeve 6 is fitted to the spool 3, and a circumferential groove is formed on the fitting surface of both, and a pump port PP and a tank port are communicated via this circumferential groove. 11 degrees and left and right steering bows) St, SR are formed in the sleeve 6.

The spool 3 is moved in the axial direction from the neutral position (the state shown in FIG. 3) by the rotation of the worm shaft 2, and is connected to the left steering port S1. When the spool 3 is in the left steering position, the right steering port 311 communicates with PP (when the spool 3 is in the left steering position), and with the tank port M2 and the right oil chamber R when the spool 3 is in the right steering position and the neutral position. It communicates with the pump port PP when it is in the left steering position and with the tank bow 1 and old when it is in the left steering position and the neutral position. When the spool 3 is in the neutral position, the pump port hPP is also in communication with the tank port I/old and M2.

(Problem to be Solved by the Invention) In the prior art, when the handle is not moved,
That is, when the spool 3 is in the neutral position, the pressure oil from the pump P only passes through the control valve 1, does no work, and is simply returned to the tank, resulting in energy loss. .

The present invention provides a hydraulic take-out port I on the sleeve, so that when the spool is in the neutral position, the pressure oil supplied from the pump port is taken out from the hydraulic take-out port, so that the oil pressure can be used effectively. This is a power steering device controller that can solve the problems of the prior art.
1:] - Aims to serve Leharbu.

(Means for Solving the Problems) A specific configuration for solving the problems in the present invention includes a spool 3, a sleeve 6 fitted to the spool 3, a pump port I'P formed in the sleeve 6, a tank port H and It has left and right steering ports SL and Sll, and the left steering port s
1. is the pump port P when spool 3 is in the left steering position.
When the spool 3 is in the right steering position, the right steering port 317 communicates with the pump port 1-r'P and communicates with the tank bow 1-r'P when the spool 3 is in the right steering position and the neutral position. In the control valve of the power steering device that communicates with the tank port gate when the spool 3 is in the steering position and the neutral position, the sleeve 6 has a valve that communicates with the pump port PP when the spool 3 is in the neutral position and is closed when the spool 3 is in the left-right steering position. A hydraulic pressure outlet port O is formed therein.

(Function) When the handle is not moved, the spool 3 is in the neutral position, and the left and right steering bows) SL and SR are connected to the tank port old and M2, respectively, and at the same time, the oil pressure take-out bow) Q is the pump port. It communicates with PP and is supplied with pressure oil.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

In Fig. 1, reference numeral 1 denotes a control valve of a power steering device, in which a spool 3 and centering plates 4A, 4B are fitted onto a worm shaft 2, and needle bearings and washers are interposed on both sides of the control valve, and the valve is extracted by a NAND at the end of the shaft. It is configured to stop.

The outer peripheral surface of the spool 3 has one central circumferential groove, intermediate circumferential grooves 5B and 5C on both sides thereof, and end circumferential grooves 5D at both ends.

5E is formed, and a sleeve 6 is fitted around its outer periphery.

The sleeve 6 is fixed to the hydraulic cylinder 8 together with the shaft end cover 7, and the inner peripheral surface thereof has a shaft inner peripheral groove 9A that can communicate with the central peripheral groove 5A and each of the intermediate peripheral grooves 5B and 5C on both sides thereof.
, 9B, each intermediate circumferential groove 5B, 5C, and each end circumferential groove 5D, 5
Shaft outer circumferential grooves 9C and 9[1 that can communicate with E are formed.

The sleeve 6 also includes a circumferential protrusion 1. between each shaft inner circumferential groove 9A, 9B and shaft outer circumferential groove 9C, 9D. ], A, ]], B has a pump port PPL facing the intermediate circumferential grooves 5B and 5C,
PI"2 is formed and connected to a power steering hydraulic pump P.

Steering ports SR, S1. are formed, one for left steering, and the other for right steering. In the embodiment, the steering port S1 is for left steering, and the steering port SR is for left steering, which is connected to the oil sump where the sexy shaft I is placed (☆). It is for right steering connected to the oil chamber R where the worm shaft is located.

At both wheel ends of the sleeve 5, tank ports 1 and 2 are formed opposite to the end circumferential grooves 5D and 5H, and are connected to a power steering tank T or a tank substituted for a transmission case of 1 to 1 to 1. There is. This tank port old, M
2 is formed by cutting out the shaft end of the sleeve 6, but it may also be a hole.

Further, a circumferential protrusion 11 between the shaft inner circumferential grooves 9A and 9B of the sleeve 6
A hydraulic pressure outlet port 0 is formed in C, facing the central circumferential groove 5A, and this hydraulic pressure outlet port hQ is connected to an actuator 13 attached to the traveling vehicle.

Examples of this actuator 13 include a hydraulic clutch for shifting gears of a transmission or switching forward/backward, a hydraulic clutch for front wheel power connection/disconnection of a four-wheel drive, or a hydraulic clutch for switching double speed, etc., and extracting pressure oil can be used for their operation. By connecting it to the suction side as a hydraulic pump, pressure oil can be used to reduce the pump load.

That is, as shown on the side in FIG. The oil pressure is output from the oil pressure take-out port 0 through the left and right steering ports SL, and is supplied to the actuator 13.

SR is communicated with tank port MLM2 via end circumferential grooves 5D + 5E.

As shown in the lower part of FIG. 1, when the spool 3 is in the left steering position, the pump port PP2 communicates with the left steering port 5L via the intermediate circumferential groove 50 and the shaft outer circumferential groove 9D, and the pressure oil The oil chamber LL is supplied with oil, the hydraulic pressure take-out port 0 is closed by the circumferential protrusions JIB and IIC coming into contact with the circumferential protrusions of the spool 3, and the right steering port SR connects the shaft outer circumferential groove 9C and the shaft end circumferential groove 5D. It communicates with the old tank port through. When the spool 3 is placed in the right steering position, the pump port PP1 communicates with the right steering port SR, and the hydraulic pressure extraction port is closed.

In FIG. 1, 1.4A and 14B are centering springs housed in the sleeve 6, and plungers 15A are located on both sides of the centering spring 14B.

15B is placed.

Incidentally, in the above embodiment, the steering ports S17, 51? The left and right may be reversed, and each port PPI, PP2 . Sl1
．． S.R., Ml.

The position of 0 can also be changed, and the present invention is also applicable to other types of power steering devices.

Fig. 2.3 shows an example of an actuator operating device configured to automatically operate required actuators using pressure oil from a power steering hydraulic pump when the handle is rotated beyond a certain angle.

For example, when a tractor turns over a certain angle,
There are cases where the front wheels of a four-wheel drive vehicle are set to double speed to make a small radius turn, one brake is activated to make a small radius turn, and the mounting machine is lifted.

The front wheel double speed switching described above mechanically detects the steering operation of the front wheels and operates the transmission hydraulic clutch, but the pressure oil for the hydraulic clutch is supplied by a hydraulic pump that sends pressure oil to the hydraulic system for lifting and lowering the work equipment. The one-sided brake operation is not automated, and the mounting operation grip is manually operated.

The actuator actuating device 17 of this example is provided with sensors 21A, 21.8 on the hydraulic cylinder 8 of the power steering device 18, which are actuated by the ball nut 20 when the handle 19 is rotated by a certain angle.
Switching valves ↑ 22A and 22B operated by 21B are provided to constitute the handle operating angle detection means 23, and the hydraulic pump P
Switching throttle valve 2 to the circuit from control j-roll valve 1
4 is provided and an oil passage 25 is connected, and this oil passage 25 is connected to the actuator 26A via the switching valves 22A and 22B.
, 26B, and this oil passage 25 and the switching throttle valve 24
are connected by a pilot oil passage 27.

Therefore, when the handle 19 is steered left and right within a certain angle range, the switching valves 22A and 22B do not operate, and the switching throttle valve 24 allows pressure oil from the hydraulic pump P to flow to the control valve 1 in a non-throttled state.

On the other hand, when the steering wheel 19 is steered left or right beyond a certain angle (for example, 30 to 35 degrees when the front wheels are used twice), the ball nut 20 operates the sensors 21A and 211 [-], and the switching valve 22A or 22B is activated. is activated, oil passage 25
is connected to the actuator 268 or 26B, and the oil passage 25
Each time the pressure is increased, the switching throttle valve 24 is switched to the throttle state via the Byronto oil passage 27, and a part of the pressure oil from the hydraulic pump P is transferred to the actuator 26A or 2.
It is supplied to the 6B side.

The actuator 26 is a hydraulic clutch for shifting the front wheels of a four-wheel drive system to 1.5 to 2 times the speed of the rear wheels;
Hydraulic cylinder 1 - Hydraulic cylinder for brake operation, hydraulic cylinder for rotating the operating lever of the hydraulic device for lifting and lowering the work equipment in the lifting direction, etc., can be used for turning operation using the pressure oil of the power steering pump P. It can be activated automatically at the same time.

(Effects of the Invention) According to the present invention described in detail above, the sleeve 6 has a hydraulic pressure outlet port 0 that communicates with the pump port 1-PP when the spool 3 is in the neutral position and is closed when the spool 3 is in the left-right steering position. Therefore, when the power steering is not used without moving the steering wheel, the pressure oil from the pump P can be taken out from the hydraulic pressure outlet port 0]1 and can be effectively used for operating the actuator 13, etc., and no pressure oil is used. It is possible to eliminate energy loss caused by

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the present invention, and Fig. 2 shows an example of the actuator actuating device. The explanatory diagram and Fig. 3 are cross-sectional views showing the conventional technology of the control valve. ...actuator, ■) ...pump, r'PI, PP2
...Pump port, SI? ...Right steering pump, SL
...Left steering pump, old, M2...Tank port, 0
...Hydraulic pressure extraction port. Patent Applicant Tetsucho Kubota Stock Exchange Procedures Amendment (1, 4 A, 1. Indication of Case 1999 Patent Application No. 13331.7 2, Name of Invention Power Steering Device Controller 1-1= 1- Luharso 3
, Relationship with the case of the person making the amendment Patent applicant Name (1,05) Kubo 11] Ironworks 8 Co., Ltd. 4
Agent 1013 Mikuriya, Higashiosaka City, Osaka Prefecture Telephone: 06 (782) 6917/6918 Heisei
Year, month, day (voluntary) 6. Subject of amendment/Detailed explanation of the invention in the specification/Brief explanation of the drawings in the specification/Drawing 7. Contents of amendment (1) Specification, page 9 From line 6 to page 11, line 13, [
Figure 2.3...Can be done 6 Delete 1.

Claims (1)

[Claims] (1) Spool (3) and sleeve (6) fitted to it
) and the pump port (PP) formed in the sleeve (6).
, tank port (M) and left/right steering port (SL) (S
R), and the left steering port (SL) has a spool (
3) communicates with the pump port (PP) when it is in the left steering position, and communicates with the tank port (PP) when it is in the right steering position and neutral position.
M), and the right steering port (SR) communicates with the spool (
3) communicates with the pump port (PP) when it is in the right steering position, and communicates with the tank port (PP) when it is in the left steering position and neutral position.
In the control valve of the power steering device that communicates with the sleeve (6), the spool (3
) communicates with the pump port (PP) when it is in the neutral position and is closed when it is in the left/right steering position.
) is formed in a control valve for a power steering device.