An axial piston pump pilot pressure reducing valve assembly

Abstract

The application discloses an axial plunger pump pilot pressure-reducing valve assembly, high-pressure oil directly introduced from a plunger pump outlet enters the pilot pressure-reducing valve assembly, is reduced by the action of a valve core and a spring, and then outputs pressure oil with a constant pressure value of 3.0-3.3 MPa, and then the pressure oil with the secondary pressure changing with the control current output by an electromagnetic proportional pressure-reducing valve is used for controlling the swing angle of a swash plate of the plunger pump. The axial plunger pump pilot pressure-reducing valve assembly can reduce an externally connected pilot oil pump, has simple pipeline arrangement and simple structure, and has low manufacturing cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of axial piston pump, and particularly relates to a pilot pressure reducing valve assembly for realizing variable power function of an axial piston pump. BACKGROUND

[0002] The axial piston pump is used to convert mechanical energy into pressure energy to provide power source for a hydraulic system. In actual work, the load on the engineering machinery is constantly changing, and the hydraulic pump needs to adjust the flow and pressure output at any time when the load changes, so a variable mechanism is needed to adjust the swash plate angle at any time to control the displacement output. However, the existing pilot pressure reducing valve assembly of the axial piston pump needs to be connected with an external pilot oil, and the pipeline arrangement is complex, which leads to a complex structure of the entire pilot control pipeline and high manufacturing cost. SUMMARY

[0003] The present application provides a pilot pressure reducing valve assembly of an axial piston pump, which provides control pressure oil for the variable mechanism of the axial piston pump, has the advantages of reducing external oil source, reducing pipeline arrangement, simple structure and cost saving.

[0004] The purpose of the present application is achieved by the following technical solutions:

[0005] A pilot pressure reducing valve assembly of an axial piston pump, comprising a pilot valve body, a mounting seat, a spring, a spring seat, a valve core, a first screw plug, a second screw plug, an electromagnetic proportional pressure reducing valve, a screw, a throttling plug and a plum blossom plug:

[0006] One side surface A of the pilot valve body is provided with four screw mounting holes penetrating through the valve body, a third oil inlet channel and a first oil outlet channel; the four screw mounting holes penetrating through the valve body are used to fix the entire pilot pressure reducing valve assembly of the axial piston pump and the piston pump body through a connecting piece; a fourth oil inlet channel and a second oil inlet channel are provided on a top surface B adjacent to the side surface A; a valve core and a first screw plug mounting hole, a second screw plug mounting hole and an electromagnetic pressure reducing valve mounting hole are sequentially provided from top to bottom on another side surface C adjacent to the side surface A; the first oil outlet channel and the electromagnetic pressure reducing valve mounting hole are through;

[0007] In addition to the four screw mounting holes penetrating through the valve body, a first oil inlet channel, a second oil outlet channel and a third oil outlet channel are provided on another side surface A opposite to the side surface A of the pilot valve body; a first oil outlet channel is provided on a bottom surface B opposite to the top surface B of the pilot valve body; a second oil outlet channel and a mounting seat hole are provided on another side surface C opposite to the side surface C of the pilot valve body, the mounting seat hole and the first oil outlet channel are through, the first oil outlet channel and the second oil outlet channel are through, and the second oil outlet channel and the third oil outlet channel are through;

[0008] The first oil inlet channel and the second oil inlet channel are through, the second oil inlet channel is through with the valve core and the first plug installation hole, the valve core and the first plug installation hole are through with the third oil inlet channel, the third oil inlet channel is a stepped hole, the third oil inlet channel is through with the fourth oil inlet channel, the fourth oil inlet channel is through with the electromagnetic pressure reducing valve installation hole, and the electromagnetic pressure reducing valve installation hole is through with the first oil outlet channel, the second oil outlet channel and the third oil discharge channel.

[0009] The mounting seat is screw-connected with the mounting seat hole, a circular hole is formed in the end of the mounting seat in contact with the spring, and the spring is installed in the circular hole; the end of the spring is abutted against one end of the spring seat, the other end of the spring seat is connected with the valve core, and the valve core, the spring seat and the spring are installed in the valve core and the first plug installation hole which are stepped holes and are sealed by the first plug; the electromagnetic proportional pressure reducing valve is installed in the electromagnetic pressure reducing valve installation hole on the side C of the pilot valve body and is installed in the second screw installation hole by a fastener, so that the electromagnetic proportional pressure reducing valve is installed on the pilot valve body; two plum blossom plugs are installed on the stepped holes at the ends of the fourth oil inlet channel and the second oil inlet channel, so as to seal the ends of the fourth oil inlet channel and the second oil inlet channel; and the electromagnetic proportional pressure reducing valve is used to output secondary pressure oil whose pressure changes with current.

[0010] The throttle plug is installed on the stepped hole at the end of the first oil inlet channel on the side A' of the pilot valve body 1, so as to play a throttling buffering role and prevent the entering hydraulic oil from impacting the valve core and the mounting seat due to too high pressure.

[0011] Further, the valve core is a stepped cylindrical structure which is coaxially arranged by a plurality of cylinders with diameters gradually increasing from bottom to top, the ball-shaped structure on one side of the valve core is connected with the spring seat, a long circular hole is formed in the valve core for oil passing, and the pressure on the valve core is balanced with the spring force.

[0012] Further, the second screw installation hole is two and is symmetrically distributed on both sides of the electromagnetic pressure reducing valve installation hole.

[0013] Further, the second plug is a PF1 / 4 plug.

[0014] Further, the first plug is a PF1 / 8 plug.

[0015] The beneficial effects of the present application are as follows:

[0016] The axial plunger pump pilot pressure reducing valve assembly of the present application introduces high pressure oil from the plunger pump outlet through internal connection, and outputs pressure oil with a constant pressure value of 3.0-3.3 MPa after the action of the valve core and the spring, and then outputs secondary pressure oil with a variable pressure after the action of the electromagnetic proportional pressure reducing valve, and the secondary pressure oil acts on the variable mechanism to change the swash plate swing angle; the present application can reduce external oil source and pipeline arrangement, has simple structure and low manufacturing cost. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a perspective view of the axial plunger pump pilot pressure reducing valve assembly of the present application;

[0018] Figure 2 It is a sectional view of the spring, spring seat and valve core installation of the present application.

[0019] Figure 3 It is a perspective view of the axial plunger pump pilot pressure reducing valve assembly of the present application from another angle.

[0020] Figure 4 It is a three-dimensional view and perspective view of the pilot valve body 1 of the axial plunger pump of the present application from one angle.

[0021] Figure 5 It is a three-dimensional view and perspective view of the pilot valve body 1 of the axial plunger pump of the present application from another angle.

[0022] Figure 6 It is a circumferential side view of the valve core.

[0023] Figure 7 It is a circumferential side view of the electromagnetic proportional pressure reducing valve.

[0024] In the figure, 1 is a pilot valve body; 2 is a mounting seat; 3 is a spring; 4 is a spring seat; 5 is a valve core; 6 is a first plug; 7 is a second plug; 8 is an electromagnetic proportional pressure reducing valve; 9 is an M4 screw; 10 is a throttling plug; 11 is a plum blossom plug; 101 is a first oil outlet flow channel; 102 is a third oil inlet flow channel; 103 is a first screw mounting hole; 104 is a valve core and first plug mounting hole; 105 is a second screw mounting hole; 106 is an electromagnetic pressure reducing valve mounting hole; 107 is a second oil inlet flow channel; 108 is a fourth oil inlet flow channel; 109 is a first oil inlet flow channel; 110 is a first oil discharge flow channel; 111 is a second oil discharge flow channel; 112 is a third oil discharge flow channel; 113 is a second oil outlet flow channel; and 114 is a mounting seat hole. DETAILED DESCRIPTION

[0025] The present application will be described in detail below according to the drawings and preferred embodiments, and the purposes and effects of the present application will become more apparent, and it should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0026] As Figures 1-3 shown in the figure, the axial plunger pump pilot pressure reducing valve assembly of the present embodiment comprises a pilot valve body 1, a mounting seat 2, a spring 3, a spring seat 4, a valve core 5, a first screw plug 6, a second screw plug 7, an electromagnetic proportional pressure reducing valve 8, a screw 9, a throttle plug 10 and a hexagonal plug 11.

[0027] As Figure 4 shown in the figure, it is a three-dimensional view and perspective view of the pilot valve body 1. One side A of the pilot valve body 1 is provided with four screw mounting holes 103 penetrating the valve body, a third oil inlet channel 102 and a first oil outlet channel 101; the four screw mounting holes 103 penetrating the valve body are used to fix the entire axial plunger pump pilot pressure reducing valve assembly and the plunger pump body through connecting members; the top surface B adjacent to the side surface A is provided with a fourth oil inlet channel 108 and a second oil inlet channel 107. The other side surface C adjacent to the side surface A is provided with the valve core and the first screw plug mounting hole 104, the second screw plug mounting hole 105 and the electromagnetic pressure reducing valve mounting hole 106 from top to bottom. The second screw plug mounting hole 105 is two, symmetrically distributed on both sides of the electromagnetic pressure reducing valve mounting hole 106. The first oil outlet channel 101 and the electromagnetic pressure reducing valve mounting hole 106 are through.

[0028] As Figure 5 shown in the figure, it is a three-dimensional view of another perspective of the pilot valve body 1, which is exactly complementary to Figure 4 . As can be seen from Figure 5 , the other side surface A' opposite to the side surface A of the pilot valve body 1 is provided with a first oil inlet channel 109, a second oil outlet channel 113 and a third oil discharge channel 112 in addition to the four screw mounting holes 103 penetrating the valve body. The bottom surface B' opposite to the top surface B of the pilot valve body 1 is provided with a first oil discharge channel 110. The other side surface C' opposite to the side surface C of the pilot valve body 1 is provided with a second oil discharge channel 111 and a mounting seat hole 114, the mounting seat hole 114 and the first oil discharge channel 110 are through, the first oil discharge channel 110 and the second oil discharge channel 111 are through, and the second oil discharge channel 111 and the third oil discharge channel 112 are through.

[0029] As can be seen from the figure, the first oil inlet channel 109 and the second oil inlet channel 107 are through, the second oil inlet channel 107 and the valve core and the first screw plug mounting hole 104 are through, the valve core and the first screw plug mounting hole 104 are through with the third oil inlet channel 102, the third oil inlet channel 102 is a stepped hole, the third oil inlet channel 102 is through with the fourth oil inlet channel 108, the fourth oil inlet channel 108 is through with the electromagnetic pressure reducing valve mounting hole 106, and the electromagnetic pressure reducing valve mounting hole 106 is through with the first oil outlet channel 101, the second oil outlet channel 113 and the third oil discharge channel 112.

[0030] Back toFigure 1 and Figure 2 The mounting seat 2 is installed in the mounting seat hole 114 of the side C' of the pilot valve body 1, and the mounting seat hole 114 of the side C' is through with the spool and the first plug mounting hole 104 of the side C. The stepped hole at the end of the third oil inlet flow channel 102 and the second oil outlet flow channel 101 respectively installs a second plug 7, which is a PF1 / 4 plug. The end of the third oil inlet flow channel 102 and the second oil outlet flow channel 101 can be used as a pressure measuring port to measure the pressure after pressure reduction.

[0031] As shown in Figure 1 , the outer periphery of the mounting seat 2 is provided with external threads for mating connection with the internal threads in the mounting seat hole 114. As shown in Figure 2 , the inside of the end of the mounting seat 2 in contact with the spring is provided with a circular hole for installing the spring 3. The end of the spring 3 abuts against one end of the spring seat 4, and the other end of the spring seat 4 is connected with the spool 5. The spring 3, the spring seat 4 and the spool 5 are all installed inside the spool and the first plug mounting hole 104, which is a stepped hole, and the end is sealed by the first plug 6. The first plug 6 is a PF1 / 8 plug. As shown in Figure 6 , the spool 5 is a stepped cylindrical structure, which is coaxially arranged by several cylinders with gradually increasing diameters from bottom to top. One side of the spool 5 is a spherical structure connected with the spring seat 4, and a long circular hole is opened in the inside of the spool 5 for oil passage. The pressure on the spool 5 is balanced with the spring force.

[0032] Returning to Figure 1 , the electromagnetic proportional pressure reducing valve 8 is installed in the electromagnetic pressure reducing valve mounting hole 106 of the side C of the pilot valve body 1, and is installed on the pilot valve body 1 by being installed in the second screw mounting hole 105 through two screws 9. Two star plugs 11 are respectively installed in the stepped holes at the ends of the fourth oil inlet flow channel 108 and the second oil inlet flow channel 107 for sealing the ends of the fourth oil inlet flow channel 108 and the second oil inlet flow channel 107. The electromagnetic proportional pressure reducing valve 8 is used to output secondary pressure oil with pressure varying with current, and the structure is shown in Figure 7 .

[0033] As shown in Figure 3 , the throttle plug 10 is installed in the stepped hole at the end of the first oil inlet flow channel 109 on the side A' of the pilot valve body 1, which plays a throttling and buffering role to prevent the incoming hydraulic oil pressure from being too high to impact the spool 5 and the mounting seat 2.

[0034] The hydraulic oil circuit of the entire axial piston pump pilot pressure reducing valve assembly is introduced as follows:

[0035] As shown in Figure 1 , the fourth oil inlet flow channel 108 is connected with the second oil inlet flow channel 107 through the second oil inlet flow channel 107, and the second oil inlet flow channel 107 is connected with the first oil inlet flow channel 109 through the first oil inlet flow channel 109. The fourth oil inlet flow channel 108 is connected with the second oil outlet flow channel 101 through the second oil outlet flow channel 101, and the second oil outlet flow channel 101 is connected with the first oil outlet flow channel 110 through the first oil outlet flow channel 110.As shown in the red oil path, the high-pressure oil from the plunger pump outlet first enters the first inlet channel 109 through the throttle plug 10 on the side A′ of the pilot valve body 1, then reaches the second inlet channel 107, and then reaches the valve core and the first plug mounting hole 104. The hydraulic pressure generated by the valve core 5 installed in the first plug mounting hole 104 is balanced with the spring force in the mounting seat 2, and a pressure oil with a constant pressure value of 3.0~3.3MPa is output. This pressure oil passes through the third inlet channel 102, then through the fourth inlet channel 108, and reaches the electromagnetic pressure reducing valve mounting hole 106. By adjusting the current of the electromagnetic proportional pressure reducing valve 8, which varies from 0 to 750mA, a secondary pressure oil with an output pressure varying from 0 to 3.0MPa flows out from the second outlet channel 113, acting on the variable mechanism on the plunger pump, thereby controlling the swashplate angle and changing the displacement output. Simultaneously, as... Figure 1 As shown in the blue oil circuit, when the hydraulic oil acts on the valve core, a small amount of oil leaks into the mounting seat hole 114, then flows to the first drain channel 110, then through the second drain channel 111, and then to the third drain channel 112. At the same time, the oil leaking from the electromagnetic proportional pressure reducing valve 8 also flows out from the third drain channel 112 into the piston pump housing.

[0036] The first oil outlet channel 101 and the electromagnetic pressure reducing valve mounting hole 106 are connected. Because the stepped hole at the end of the first oil outlet channel 101 is sealed by the second screw plug 7, the oil in the first oil outlet channel 101 flows out through the electromagnetic pressure reducing valve mounting hole 106 and the second oil outlet channel 113.

[0037] The installation process of the axial piston pump pilot pressure reducing valve assembly in this embodiment is as follows:

[0038] The first screw plug 6, the second screw plug 7, and the plum blossom plug 11 are fixed to the pilot valve body 1 by threaded connection; the valve core 5 is installed in the valve core and the first plug mounting hole 104, with the spherical end of the valve core 5 facing the mounting seat hole 114; the spring 3 is placed in the inner hole of the mounting seat 2, and then the spring seat 4 is placed on the spring 3. Finally, the three parts are installed together into the valve core and the first plug mounting hole 104, with the ball socket of the spring seat 4 and the spherical end of the valve core 5 in contact; the electromagnetic proportional pressure reducing valve 8 is installed in the electromagnetic pressure reducing valve mounting hole 106, and two M4 screws 9 are installed and tightened; finally, the throttle plug 10 is installed in the first oil inlet channel 109.

[0039] This invention can reduce the need for external oil sources and pipeline layout, and has a simple structure and low cost.

[0040] Those skilled in the art can understand that the above description is only the preferred examples of the present application and is not used to limit the present application, and although the present application is described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacements for part of the technical features. Any modification, equivalent replacement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A pilot pressure reducing valve assembly for an axial piston pump, characterized in that, Includes pilot valve body (1), mounting base (2), spring (3), spring seat (4), valve core (5), first screw plug (6), second screw plug (7), electromagnetic proportional pressure reducing valve (8), screw (9), throttle plug (10), and plum blossom plug (11): The pilot valve body (1) has four through-hole screw mounting holes (103) on one side A, as well as a third oil inlet channel (102) and a first oil outlet channel (101); the four through-hole screw mounting holes (103) are used to fix the entire axial piston pump pilot pressure reducing valve assembly and piston pump body through the connector; a fourth oil inlet channel (108) and a second oil inlet channel (107) are provided on the top surface B adjacent to side A; the other side C adjacent to side A has valve core and first plug mounting hole (104), second screw mounting hole (105) and electromagnetic pressure reducing valve mounting hole (106) sequentially opened from top to bottom; the first oil outlet channel (101) and the electromagnetic pressure reducing valve mounting hole (106) are connected; On the other side A′ opposite to the pilot valve body, in addition to the four screw mounting holes (103) that penetrate the valve body, a first oil inlet channel (109), a second oil outlet channel (113), and a third oil drain channel (112) are also provided; on the bottom surface B′ opposite to the top surface B of the pilot valve body, a first oil drain channel (110) is provided; on the other side C′ opposite to the pilot valve body, a second oil drain channel (111) and a mounting seat hole (114) are provided, the mounting seat hole (114) and the first oil drain channel (110) are connected, the first oil drain channel (110) and the second oil drain channel (111) are connected, and the second oil drain channel (111) and the third oil drain channel (112) are connected. The first oil inlet channel (109) and the second oil inlet channel (107) are connected. The second oil inlet channel (107) is connected to the valve core and the first plug mounting hole (104). The valve core and the first plug mounting hole (104) are connected to the third oil inlet channel (102). The third oil inlet channel (102) is a stepped hole. The third oil inlet channel (102) is connected to the fourth oil inlet channel (108). The fourth oil inlet channel (108) is connected to the electromagnetic pressure reducing valve mounting hole (106). The electromagnetic pressure reducing valve mounting hole (106) is connected to the first oil outlet channel (101). The second oil outlet channel (113) and the third oil drain channel (112) are connected; the mounting base (2) is installed in the mounting base hole (114) on the side C' of the pilot valve body (1), and the mounting base hole (114) on the side C' is connected to the valve core and the first plug mounting hole (104) on the side C; a second screw plug 7 is installed in the stepped hole at the end of the third oil inlet channel (102) and the second oil outlet channel (101); the ends of the third oil inlet channel (102) and the second oil outlet channel (101) can both be used as pressure measuring ports to connect external sensors to measure the pressure after decompression; The mounting base (2) is threadedly connected to the mounting base hole (114); a round hole is opened inside the end of the mounting base (2) that contacts the spring for installing the spring (3); the end of the spring (3) abuts against one end of the spring seat (4), and the other end of the spring seat (4) is connected to the valve core (5). The spring (3), spring seat (4), and valve core (5) are all installed inside the valve core and the first plug mounting hole (104). The valve core and the first plug mounting hole (104) are stepped holes, and the ends are sealed by the first screw plug (6); the electromagnetic proportional pressure reducing valve (8) is installed in the first The electromagnetic proportional pressure reducing valve (8) is installed in the electromagnetic pressure reducing valve mounting hole (106) on the side C of the pilot valve body (1) and in the second screw mounting hole (105) by fasteners, thereby installing the electromagnetic proportional pressure reducing valve (8) on the pilot valve body (1); two plum blossom plugs (11) are respectively installed on the stepped holes at the ends of the fourth oil inlet channel (108) and the second oil inlet channel (107) to seal the ends of the fourth oil inlet channel (108) and the second oil inlet channel (107); the electromagnetic proportional pressure reducing valve (8) is used to output secondary pressure oil whose pressure changes with the current; The throttle plug (10) is installed on the stepped hole at the end of the first oil inlet channel (109) on the side A′ of the pilot valve body 1. It is used to throttle and buffer, and prevent the pressure of the incoming hydraulic oil from being too high and impacting the valve core (5) and the mounting seat (2).

2. The axial piston pump pilot pressure reducing valve assembly according to claim 1, characterized in that, The valve core (5) is a stepped cylindrical structure, which is composed of several cylinders with gradually increasing diameter from bottom to top arranged coaxially. The spherical structure on one side of the valve core (5) is connected to the spring seat (4). There is an elongated hole inside the valve core (5) for oil to pass through. The pressure on the valve core (5) is balanced with the spring force.

3. The axial piston pump pilot pressure reducing valve assembly according to claim 1, characterized in that, There are two second screw mounting holes (105), which are symmetrically distributed on both sides of the electromagnetic pressure reducing valve mounting hole (106).

4. The axial piston pump pilot pressure reducing valve assembly according to claim 1, characterized in that, The second plug (7) is a PF1 / 4 plug.

5. The axial piston pump pilot pressure reducing valve assembly according to claim 1, characterized in that, The first screw plug (6) is a PF1 / 8 screw plug.

Images