CN116025734A - Variable motor pressure control valve and design method - Google Patents

Abstract

The invention discloses a variable motor pressure control valve and a design method, wherein the variable motor pressure control valve comprises a valve sleeve, a valve core is arranged in the valve sleeve, a first oil port, a second oil port and a control oil port are arranged on the valve sleeve, a step close to the first oil port is arranged on the outer peripheral surface of the valve core, a first through hole is arranged in the axial direction of the valve core, a second through hole communicated with the first through hole is arranged in the radial direction of the valve core, a first annular groove communicated with the second oil port is arranged on the outer peripheral surface of the valve core, a second annular groove is arranged between the first annular groove and the second through hole, a third through hole communicated with the first through hole is arranged on the bottom surface of the second annular groove, and the second oil port is communicated with the control oil port through a damping hole. The invention has the advantages of reducing the failure rate of the motor, along with good replaceability and low improvement cost.

Description

Variable motor pressure control valve and design method

Technical Field

The invention belongs to the field of variable motors, and particularly relates to a variable motor pressure control valve and a design method thereof.

Background

The output torque of a variable displacement motor (motor for short) is proportional to the product of motor displacement and pressure; in the use of the motor, the working condition that the load suddenly increases under the condition of small displacement of the motor can be met, which can lead to 1) insufficient output torque under the condition of small displacement of the motor and 2) the use of the motor under the condition of overpressure. To cope with the above problems, a pressure control valve is usually added to the motor for the purpose of 1) ensuring that the motor can provide sufficient output torque; 2) And the motor is protected from the use under the extreme working condition of overpressure. Such as pressure control valves (HD 1D, EP 2D) commonly used in conjunction with hydraulic proportional control and electric proportional control in a Lishile L6VE/M series hydraulic motor,

the structure of the existing pressure control valve (HD 1D, EP 2D) is shown in fig. 4, and the existing pressure control valve comprises a valve sleeve 1, wherein a valve core 2 is arranged in the valve sleeve 1, a first oil port 10, a second oil port 11 and a control oil port 12 are arranged on the valve sleeve 1, a step 20 which is close to the first oil port 10 and communicated with the first oil port 10 is arranged on the outer peripheral surface of the valve core 2, a first through hole 21 is axially arranged on the valve core 2, a second through hole 22 which is communicated with the first through hole 21 is radially arranged on the valve core 2, a first annular groove 23 which is communicated with the second oil port 11 is arranged on the outer peripheral surface of the valve core 2, a second annular groove 24 is arranged between the first annular groove 23 and the second through hole 22, and a third through hole 25 which is communicated with the first through hole 21 is arranged on the bottom surface of the second annular groove 24.

As shown in fig. 3, the first oil port 10 is connected with the working oil port a of the motor through the one-way valve C, the second oil port 11 is connected with the working oil port B of the motor through the one-way valve D, the control oil port 12 is connected with the large end of the variable cylinder of the motor, the first through hole 21 is communicated with the oil return port T of the motor, and the outlet end of the one-way valve C is connected in parallel with the outlet end of the one-way valve D.

In the use process, the problem that the motor cannot be changed into small displacement is found to occur sometimes, and the failure rate of the motor is high.

Disclosure of Invention

The invention aims to provide a variable motor pressure control valve and a design method. The invention has the advantages of reducing the failure rate of the motor, along with good replaceability and low improvement cost.

The technical scheme of the invention is as follows: the utility model provides a variable motor pressure control valve, including the valve pocket, be equipped with the case in the valve pocket, be equipped with first hydraulic fluid port on the valve pocket, second hydraulic fluid port and control hydraulic fluid port, be equipped with the step that is close to the first hydraulic fluid port of intercommunication on the outer peripheral face of case, be equipped with first through-hole on the case axial, the case radially is equipped with the second through-hole with first through-hole intercommunication, the second through-hole is located between first hydraulic fluid port and the control hydraulic fluid port, be equipped with the first ring channel with the second hydraulic fluid port intercommunication on the outer peripheral face of case, be equipped with the second ring channel between first ring channel and the second through-hole, be equipped with the third through-hole with first through-hole intercommunication on the bottom surface of second ring channel, the second hydraulic fluid port passes through the damping hole intercommunication control hydraulic fluid port.

According to the design method of the variable motor pressure control valve, the damping hole is arranged between the second annular groove and the first annular groove, so that the second oil port is communicated with the control oil port through the damping hole.

Compared with the prior art, the invention is provided with the damping hole on the basis of the existing pressure control valve (HD 1D, EP D), and the damping hole is communicated with the control oil port and the second oil port. The applicant finds through long-time research that the condition that the motor can not become to little discharge capacity basically takes place when load pressure risees to a certain extent, load pressure again instantaneously reduces, and at this moment, the motor can appear because of control chamber oil circuit fluid pressure is higher than load pressure, leads to two check valves to close simultaneously to die, and control chamber high pressure oil can't discharge, and the case can't return, makes the motor variable cylinder big end still lead to the oil return always, can't return to the low discharge capacity yet to resume. According to the invention, the control oil port and the second oil port are communicated through the damping hole, so that under the condition that the check valve is closed, high-pressure oil in the control cavity can still be smoothly discharged, the valve core can be smoothly returned, the oil return is not conducted to the large end of the variable cylinder of the motor, the motor can be restored to small discharge capacity, and the failure rate of the motor is low. In addition, the invention is improved on the basis of the existing pressure control valve, the external dimension and the assembly dimension are not changed, the existing pressure control valve can be directly replaced, the replacement is good, the improvement cost is low, and the invention can be basically regarded as zero cost. Therefore, the invention has the advantages of reducing the failure rate of the motor, along with good replaceability and low improvement cost.

Drawings

Fig. 1 is a front view of the present invention.

Fig. 2 is an enlarged view of fig. 1 at a.

Fig. 3 is a hydraulic schematic of the pressure control valve on a variable displacement motor.

Fig. 4 is a front view of a prior art pressure control valve.

The marks in the drawings are: 1-valve sleeve, 10-first oil port, 11-second oil port and 12-control oil port; 2-valve core, 20-step, 21-first through hole, 22-second through hole, 23-first annular groove, 24-second annular groove, 25-third through hole.

Detailed Description

The invention is further illustrated by the following figures and examples, which are not intended to be limiting.

Examples. The utility model provides a variable motor pressure control valve, improve on the basis of HD1D type or EP2D type pressure control valve, as shown in fig. 1 and 2, including valve pocket 1, be equipped with case 2 in the valve pocket 1, be equipped with first hydraulic fluid port 10 on the valve pocket 1, second hydraulic fluid port 11 and control hydraulic fluid port 12, be equipped with the step 20 near the intercommunication first hydraulic fluid port 10 on the outer peripheral face of case 2, be equipped with first through-hole 21 in the case 2 axial, be equipped with the second through-hole 22 with first through-hole 21 intercommunication on the case 2 is radial, second through-hole 22 is located between first hydraulic fluid port 10 and the control hydraulic fluid port 12, be equipped with the first ring channel 23 with second hydraulic fluid port 11 intercommunication on the outer peripheral face of case 2, be equipped with second ring channel 24 between first ring channel 23 and the second through-hole 22, be equipped with the third through-hole 25 with first through-hole 21 intercommunication on the bottom surface of second ring channel 24. Is characterized in that the second oil port 11 is communicated with the control oil port 12 through the damping hole 3. The damping hole 3 is in a circular ring shape and is formed between the valve sleeve 1 and the valve core 2.

Working principle: the existing pressure control valve is firstly analyzed, as shown in fig. 3, the motor is initially at a small displacement, the motor encounters a sudden load change, the system pressure rises, the system high-pressure oil acts on the step 20 through the one-way valve C (D), at the moment, the pressure control valve is positioned at the left position as seen in fig. 3, the valve core 2 moves rightwards as seen in fig. 4, the first through hole 21 is communicated with the control oil port through the second through hole 22, the large end of the variable cylinder is communicated with oil return, and the motor is variable to the large displacement. When the load pressure suddenly decreases, because the valve core 2 and the valve sleeve 1 are in extremely small clearance fit, and the check valve C is rapidly closed, the control cavity (the control cavity is formed by the oil paths of the two-dot chain line shown in fig. 2) is closed, the pressure cannot be reduced, the oil pressure acting on the step 20 cannot be reduced, the spring cannot enable the valve core 2 to move back, the large end of the variable cylinder is still normally connected with oil return, and the motor cannot recover to small displacement.

After knowing the reason that the motor cannot recover to the small displacement, the invention ensures that the second oil port 11 and the control oil port 12 are communicated by arranging the damping hole 3, so that the control cavity cannot be closed, and even if the one-way valve C is closed, the oil pressure acting on the step 20 can be reduced, so that the motor can recover to the small displacement.

Claims (2)

1. The utility model provides a variable motor pressure control valve, including valve barrel (1), be equipped with case (2) in valve barrel (1), be equipped with first hydraulic fluid port (10) on valve barrel (1), second hydraulic fluid port (11) and control hydraulic fluid port (12), be equipped with on the outer peripheral face of case (2) and be close to step (20) of intercommunication first hydraulic fluid port (10), be equipped with first through-hole (21) on case (2) axial, case (2) are equipped with second through-hole (22) with first through-hole (21) intercommunication on the radial, second through-hole (22) are located between first hydraulic fluid port (10) and control hydraulic fluid port (12), be equipped with first ring channel (23) with second hydraulic fluid port (11) intercommunication on the outer peripheral face of case (2), be equipped with second ring channel (24) between first ring channel (23) and the second through-hole (22), be equipped with on the bottom surface of second ring channel (24) with third through-hole (25) with first through-hole (21) intercommunication, its characterized in that: the second oil port (11) is communicated with the control oil port (12) through the damping hole (3).

2. The method of designing a variable motor pressure control valve according to claim 1, characterized in that: the second oil port (11) is communicated with the control oil port (12) through the damping hole (3) by arranging the damping hole (3) between the second annular groove (24) and the first annular groove (23).

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