CN215830837U - Compact structure type load sensitive valve - Google Patents

Compact structure type load sensitive valve Download PDF

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Publication number
CN215830837U
CN215830837U CN202121877231.2U CN202121877231U CN215830837U CN 215830837 U CN215830837 U CN 215830837U CN 202121877231 U CN202121877231 U CN 202121877231U CN 215830837 U CN215830837 U CN 215830837U
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Prior art keywords
valve
cavity
sleeve
spring seat
valve core
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CN202121877231.2U
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Chinese (zh)
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吴学江
陆仕
史进武
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Suzhou Liyuan Hydraulic Co ltd
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Liyuan Hydraulic Suzhou Co ltd
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Abstract

The utility model discloses a load sensitive valve with a compact structure, which comprises a valve sleeve (64) arranged in a valve body (61) of a pump power valve, wherein a valve core (63) is arranged in the valve sleeve (64); the pressure regulating valve further comprises a threaded sleeve (611) arranged at the tail end of the pump power valve body (61), a large spring seat (65) and a small spring seat (68) are sequentially arranged in the threaded sleeve (611) from front to back, the large spring seat (65) is in positioning fit with the smooth spherical surface at the tail end of the valve core (63), the tail end of the small spring seat (68) is connected with a pressure regulating screw (69), and a sealing lock nut (610) is further arranged on the pressure regulating screw (69); a small spring (67) is arranged between the large spring seat (65) and the small spring seat (68), and a large spring (66) is arranged between the large spring seat (65) and the threaded sleeve (611); and a damping plug (62) is also arranged in the front end of the valve core (63). The utility model has the characteristics of effectively reducing the installation space, reducing the production difficulty and reducing the production cost.

Description

Compact structure type load sensitive valve
Technical Field
The utility model relates to a load sensitive valve, in particular to a load sensitive valve with a compact structure.
Background
The load sensitive valve is a flow control valve that regulates the flow of the pump to the flow required by the actuator. The specific working principle is as follows: the flow rate of the pump is related to the cross-sectional area of an external sensing orifice (hereinafter referred to as a throttle valve) installed between the pump outlet and the actuator; comparing the pressures before and after the throttle valve through a load sensitive valve, and keeping the pressure drop (hereinafter referred to as the pressure drop) of the throttle valve constant, thereby keeping the flow of the pump constant; when the pressure difference is increased, the pump swings back towards a small displacement, and when the pressure difference is reduced, the pump swings back towards a large displacement until the pressure difference at the two ends of the throttle valve is restored to a set value, so that the flow of the pump is restored to the set value.
Common load-sensitive valves in the market at present, for example, in patents with patent application numbers of CN202021741604.9 and CN202020481311.5, respectively, the valve core of the load-sensitive valve has high processing precision and the valve core and the valve body both need heat treatment; as in the patent with patent application No. CN201320825991.8, although a valve sleeve and a valve core structure is adopted, the damping holes are assembled on the valve body, the oil path is complicated, the valve core machining precision is high, and the screw is used to limit the position of the valve core of the load-sensitive valve, so as to increase the volume of the valve body, increase the volume of the pump, and increase the installation space of the main machine.
In engineering machinery, a crawler machine is widely applied to mechanical construction of engineering such as transportation, hydraulic engineering, mining and the like. The hydraulic system is generally provided with hydraulic energy by parallel connection of hydraulic duplex pumps, and the hydraulic duplex pumps are generally controlled by constant power. The double pump power valve needs to be subjected to composite load sensitive control, and the pump provides large flow to the actuator in a low-pressure stage so as to improve the efficiency.
If any one of the three patents is adopted for assembling the load sensitive valve on the power valve, an installation space needs to be reserved outside the valve body; meanwhile, any one of the first two of the three patents is adopted to integrate the load-sensitive valve structure in the power valve body, and the valve body needs to be subjected to heat treatment, so that the valve body is large in size and extremely high in cost; the load-sensitive valve structure of the third patent is integrated in the power valve body, so that the structure of an internal oil circuit of the valve body is complex, the processing difficulty is high, the requirement on the processing precision of the valve core is high, and the cost is extremely high.
Therefore, the prior art has the problems of large required installation space, large processing difficulty and high cost.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a load-sensitive valve with a compact structure. The utility model has the characteristics of effectively reducing the installation space, reducing the processing difficulty and reducing the production cost.
The technical scheme of the utility model is as follows: the load sensitive valve with a compact structure comprises a valve sleeve arranged in a valve body of a pump power valve, wherein a valve core is arranged in the valve sleeve; the pressure regulating valve also comprises a threaded sleeve arranged at the tail end of the valve body of the pump power valve, a large spring seat and a small spring seat are sequentially arranged in the threaded sleeve from front to back, the large spring seat is in positioning fit with the smooth spherical surface at the tail end of the valve core, the tail end of the small spring seat is connected with a pressure regulating screw, and a sealing locking nut is further arranged on the pressure regulating screw; a small spring is arranged between the large spring seat and the small spring seat, and a large spring is arranged between the large spring seat and the threaded sleeve; and a damping plug is arranged in the front end of the valve core.
In the compact load sensitive valve, the front end of the threaded sleeve is provided with a radial semicircular hole.
In the load sensitive valve with a compact structure, a first P cavity is arranged between the front ends of the valve core and the valve sleeve and the valve body of the pump power valve; and a second P cavity is arranged between the tail ends of the valve sleeve and the valve core and between the front end of the screw sleeve and the valve body of the pump power valve.
In the compact load sensitive valve, a cavity A, a cavity B, a cavity T and a cavity X are sequentially arranged in the valve body of the pump power valve from front to back; the cavity A is matched with an oil outlet of the pump, the cavity B is communicated with a variable piston rodless cavity, and the cavity T is communicated with an oil return cavity; the X cavity is communicated with an oil outlet of the pump through a throttle valve.
In the compact load-sensitive valve, the X-cavity corresponds to the second P-cavity.
In the load sensitive valve with a compact structure, the valve sleeve comprises a valve sleeve body, and a radial hole A, a radial hole B and a radial hole T are sequentially arranged on the valve sleeve body from front to back; an annular groove is formed in the inner wall surface of the radial hole B; the tail end of the valve sleeve body is provided with a limiting step matched with the valve body of the pump power valve.
In the compact load sensitive valve, the valve core comprises a valve core body, an axial c cavity is arranged at the front end of the valve core body, and a radial a hole matched with the axial c cavity is formed in the valve core body; the middle part of the valve core body is provided with an annular control step; the annular control step is matched with the annular groove.
In the compact load sensitive valve, two ends of the annular control step are also provided with inclined chamfers.
Compared with the prior art, the utility model adopts the valve sleeve and valve core structure, and the valve sleeve and valve core structure is arranged in the pump power valve body; the load sensitive valve is integrated in a valve body of the pump power valve, an oil way is designed to lead oil from an outlet of the pump to a cavity A, lead oil from a variable piston rodless cavity to a cavity B, and a cavity T is communicated with an oil return cavity; when the pump does not work, the cavity B is communicated with the cavity T, oil in a variable piston rodless cavity of the pump is returned, and the pump is in a large displacement state; when the pump works, the load sensitive valve compares the pressures before and after the throttle valve and keeps the differential pressure of the throttle valve constant, thereby keeping the flow rate of the pump constant. When the pressure difference is increased, the valve core moves to the right, the cavity A is communicated with the cavity B, oil enters the rodless cavity of the piston, and the piston pushes the pump to swing back towards a small displacement; when the pressure difference is reduced, the valve core moves leftwards, the cavity A is blocked to be communicated with the cavity B, the cavity B is communicated with the cavity T, oil in the rodless cavity of the piston returns, the piston pushes the pump to swing back towards large displacement until the pressure difference at the two ends of the throttle valve is restored to a set value, and the flow of the pump is restored to the set value.
By adopting the structure, the structure has the following advantages:
1. the load sensitive valve is arranged in the valve body of the pump power valve, the structure of the pump is not changed, the additional installation space of the host is not required to be reserved, the installation space of the host is not occupied, the installation space can be greatly reduced, and the cost of the host can be reduced; only the valve core and the valve sleeve need to be subjected to heat treatment, and the valve body does not need to be subjected to heat treatment, so that the cost can be further reduced. Meanwhile, the load sensitive valve is arranged in the valve body, the original design of the pump is not changed, the installation of a host is convenient, and the load sensitive valve has the characteristics of small volume, compact structure, high integration level and low cost; and the different pressure differences of the throttle valve can be matched by adjusting the pretightening force of the spring according to the specific requirements of customers, so that the market competitiveness is strong.
2. The internal oil passage of the load sensitive valve is simple, simple in structure, easy to process and low in cost.
3. The two ends of the valve core annular control step are set to be inclined chamfers, so that the valve core structure is simplified, the processing difficulty is reduced, and the processing cost is reduced.
4. And a pressure equalizing groove is added on the valve core, so that the risk of clamping stagnation of the valve core in the valve sleeve is reduced.
5. And a damping hole is integrated on the valve core, so that hydraulic impact is reduced, meanwhile, the oil way of the valve body is reduced, and the processing cost is reduced.
6. The valve sleeve is a revolving body, does not need a special clamp, is easy to process and has low cost.
In conclusion, the utility model has the characteristics of effectively reducing the installation space, reducing the processing difficulty and reducing the production cost.
Drawings
FIG. 1 is a longitudinal sectional view of the present invention;
FIG. 2 is a longitudinal section view of the valve housing of the load sensitive valve;
FIG. 3 is a longitudinal section view of a valve cartridge of the load sensitive valve;
FIG. 4 is a longitudinal sectional view of the damping plug;
fig. 5 is a working principle diagram of the present invention.
The labels in the figures are: 1-pump, 2-variable piston, 3-power valve, 4-throttle valve, 5-pilot valve, 6-load sensitive valve; 61-pump power valve body, 62-damping plug, 63-valve core, 64-valve sleeve, 65-large spring seat, 66-large spring, 67-small spring, 68-small spring seat, 69-pressure regulating screw, 610-sealing lock nut, 611-screw sleeve, 612-radial semicircular hole, 613-first P cavity, 614-second P cavity, 615-A cavity, 616-B cavity, 617-T cavity, 618-X cavity, 641-valve sleeve body, 642-radial A hole, 643-radial B hole, 644-radial T hole, 645-annular groove, 646-limit step, 631-valve core body, 632-axial c cavity, 633-radial a hole, 634-annular control step, 635-inclined chamfer and 636-pressure equalizing groove, 621-damping orifice.
Detailed Description
The utility model is further illustrated by the following figures and examples, which are not to be construed as limiting the utility model.
Examples are given. The load-sensitive valve with a compact structure is shown in fig. 1 to 5, and comprises a valve sleeve 64 arranged in a valve body 61 of a pump power valve, wherein a valve core 63 is arranged in the valve sleeve 64; the hydraulic pump power valve further comprises a threaded sleeve 611 arranged at the tail end of the valve body 61 of the pump power valve, a large spring seat 65 and a small spring seat 68 are sequentially arranged in the threaded sleeve 611 from front to back, the large spring seat 65 is in positioning fit with the smooth spherical surface at the tail end of the valve core 63, the tail end of the small spring seat 68 is connected with a pressure regulating screw 69, and a sealing lock nut 610 is further arranged on the pressure regulating screw 69; a small spring 67 is arranged between the large spring seat 65 and the small spring seat 68, and a large spring 66 is arranged between the large spring seat 65 and the threaded sleeve 611; the interior of the front end of the valve core 63 is also provided with a damping plug 62.
The front end of the threaded sleeve 611 is provided with a radial semicircular hole 612.
A first P cavity 613 is arranged between the front ends of the valve core 63 and the valve sleeve 64 and the pump power valve body 61; a second P chamber 614 is provided between the rear ends of the valve sleeve 64 and the valve core 63, the front end of the threaded sleeve 611, and the pump power valve body 61.
A cavity A615, a cavity B616, a cavity T617 and a cavity X618 are sequentially arranged in the pump power valve body 61 from front to back; the cavity A615 is communicated with an oil outlet of the pump 1, the cavity B616 is communicated with a rodless cavity of the variable piston 2, and the cavity T617 is communicated with an oil return cavity; the X cavity 618 is communicated with the oil outlet of the pump 1 through a throttle valve 4.
The X cavity 618 corresponds in position to the second P cavity 614.
The valve sleeve 64 comprises a valve sleeve body 641, and a radial a hole 642, a radial B hole 643 and a radial T hole 644 are sequentially arranged on the valve sleeve body 641 from front to back; an annular groove 645 is formed in the inner wall surface of the radial hole B643; the valve housing body 641 is provided at the rear end thereof with a position-limiting step 646 engaged with the pump power valve body 61.
The valve core 63 comprises a valve core body 631, an axial c cavity 632 is arranged at the front end of the valve core body 631, and a radial a hole 633 communicated with the axial c cavity 632 is arranged on the valve core body 631; the middle part of the valve core body 631 is provided with an annular control step 634; the annular control land 634 mates with the annular groove 645.
The annular control step 634 is also provided with an angled chamfer 635 at each end.
The tail end of the valve core body 631 is further provided with a pressure equalizing groove 636.
The damping plug 62 is provided with a damping hole 621.
The front end inclined chamfer of the annular control step is N1, and the rear end inclined chamfer of the annular control step is N2.
The front end of the annular groove is M1, and the rear end of the annular groove is M2.
The valve sleeve is also provided with a threaded hole, so that the valve sleeve is convenient to assemble, easy to exchange and easy to maintain.
The front end corresponds to the left end in the figure, and the rear end corresponds to the tail end in the figure.
The valve sleeve 64 is matched with the cylindrical surface of the valve body 61 of the pump power valve to form cylindrical surface sealing; the valve core 63 is matched with the cylindrical surface of the valve sleeve 64 to form cylindrical surface sealing, and the cylindrical surfaces of the valve body 61, the valve sleeve 64 and the valve core 63 are sealed to form a sealing cavity (a first P cavity); the damping plug 62 is in threaded connection with the valve core 63; the threaded sleeve 611 is in threaded connection with the valve body 61 and is inserted into the valve body 61. The large spring seat 65 is in positioning fit with the smooth spherical surface of the valve core 63, the small spring seat 68 is positioned by a pressure regulating screw 69, and the small spring 67 is positioned by the large spring seat 65 and the small spring seat 68 respectively and assembled between the large spring seat 65 and the small spring seat 68; the large spring 66 is positioned by the threaded sleeve 611 and the large spring seat 65, and is assembled between the threaded sleeve 611 and the large spring seat 65. The pretightening force of the large spring 66 and the pretightening force of the small spring 67 are adjusted by the pressure adjusting screws.
The valve sleeve 64 is positioned by a limit step at the right end of the figure and is propped against the valve body 61 under the action of the screw sleeve and cannot move left and right.
The valve body 61, the valve sleeve 64, the valve core 63, and the screw sleeve 611 form a sealed chamber (second P chamber).
When the pump does not work, the valve core 63 is attached to the bottom of the valve body 61, the illustrated separated state is used for convenience in describing the working principle of the valve, and the positions of the rest parts are shown in fig. 1.
Two pump power valve bodies of the duplex pump are both provided with the load sensitive valve. Since the configuration of the other pump of the tandem pump is a symmetrical configuration, for the sake of describing the principle, only the control of one pump will be described.
The working principle is as follows:
the working principle of the throttle valve is as follows: when oil passes through, pressure loss is generated, namely, a certain pressure difference exists between the front and the rear of the throttle valve; the pressure difference is only related to the flow passing through and is not related to the pressure on the premise that the opening shape and the opening degree of the throttle valve and the viscosity of oil are not changed. Conversely, if the differential pressure across the throttle is maintained constant, the flow through the throttle remains constant regardless of changes in pressure.
The working principle of the load-sensitive valve is as follows:
when the pump is not operated, the valve core 63 is pressed against the bottom end (i.e., the front end) of the valve body 61 by the large spring 66 and the small spring 67. At the moment, the end of an annular control step N1 of the valve core 63 and the end of an annular groove M1 end of the valve sleeve 64 form positive covering, and the cavity A is blocked from being communicated with the cavity B; the N2 end of the annular control land of the valve spool 63 forms a positive opening with the M2 side of the annular groove of the valve sleeve 64, communicating the B chamber with the T chamber. Namely, the variable piston rodless cavity leads to the oil return cavity, and the pump is in large displacement.
When the pump starts to work, pressure oil at the outlet of the pump enters an axial cavity c of the valve core 63 through a cavity A of the valve body 61, a radial hole A of the valve sleeve 64 and a radial hole a of the valve core 63, then enters a first cavity P through a damping hole of the damping plug 62 and acts on the left end face of the valve core 63; meanwhile, pressure oil at the outlet of the pump enters a second P cavity through the throttle valve 4, the X cavity of the valve body 61 and a radial semicircular hole in the threaded sleeve 611 and acts on the right end face of the valve core 63. The pressure applied to the spool 63 by the throttle action of the throttle valve 4 is the differential pressure, and the spool 63 is applied with the urging forces of the large spring 66 and the small spring 67.
The pressure regulating screw 69 is adjusted to make the pre-tightening force of the large spring 66 and the small spring 67 equal to the acting force (the product of the pressure difference and the area of the cylindrical surface of the valve core 63) of the pressure oil acting on the valve core 63. At this time, when the pump speed rises or the pressure drops to cause the outlet flow of the pump to rise, the pressure difference between the front and the back of the throttle valve 4 also rises, the valve core 63 moves rightwards, the end of the annular control step N1 of the valve core 63 and the annular groove M1 of the valve sleeve 64 form a positive opening, and the end of the annular control step N2 of the valve core 63 and the annular groove M2 of the valve sleeve 64 form a positive cover, so that the cavity A is communicated with the cavity B, and the cavity B and the cavity T are blocked; the pressure oil passes through the cavity A of the valve body 61, the radial hole A and the radial hole B of the valve sleeve 64 enter the cavity B and then enter the variable piston rodless cavity to push the variable piston rodless cavity to swing towards a small angle, the outlet flow is reduced to a set value, the pressure difference between the front and the rear of the throttle valve is reduced to the set value, and then the valve core 63 moves leftwards and returns. When the rotation speed is reduced or the pressure is increased to cause the outlet flow of the pump to be reduced, the action process is opposite to the process. The valve core 63 moves leftwards under the action of spring force, and the end of an annular control step N1 of the valve core 63 and the end of an annular groove M1 of the valve sleeve 64 form a positive cover to block the communication between the cavity A and the cavity B; the end of the annular control step N2 of the valve core 63 and the end of the annular groove M2 of the valve sleeve 64 form a positive opening, so that the cavity B is communicated with the cavity T. Oil in the variable piston rodless cavity passes through the valve body B cavity, the valve sleeve radial holes B and T enter the T cavity of the valve body 61, the variable piston returns to the original position and swings to a large angle, and the outlet flow is increased to a set value along with the swing. The differential pressure across the throttle valve also increases to the set value, and the spool 63 moves to the right to return.
It should be noted that there is no obvious segmental process in actual operation, because the spool 63 is sensitive to follow-up, and it is always in a certain dynamic equilibrium state, keeping a certain degree of openness.
In a word, the function of the load-sensitive valve is to receive the differential pressure information from the throttle valve and convert the differential pressure into a certain opening degree, thereby controlling the swing angle of the variable piston 2, indirectly controlling the outlet flow of the pump, and finally correcting the differential pressure to a constant value to ensure that the outlet flow of the pump is a constant value.
When the customer has different requirements on the pressure difference of the load sensitive valve, the pretightening force of the large spring 66 and the pretightening force of the small spring 67 can be adjusted through the pressure adjusting screw 69.

Claims (8)

1. Compact structure type load sensing valve, its characterized in that: comprises a valve sleeve (64) arranged in a valve body (61) of a pump power valve, wherein a valve core (63) is arranged in the valve sleeve (64); the pressure regulating valve further comprises a threaded sleeve (611) arranged at the tail end of the pump power valve body (61), a large spring seat (65) and a small spring seat (68) are sequentially arranged in the threaded sleeve (611) from front to back, the large spring seat (65) is in positioning fit with the smooth spherical surface at the tail end of the valve core (63), the tail end of the small spring seat (68) is connected with a pressure regulating screw (69), and a sealing lock nut (610) is further arranged on the pressure regulating screw (69); a small spring (67) is arranged between the large spring seat (65) and the small spring seat (68), and a large spring (66) is arranged between the large spring seat (65) and the threaded sleeve (611); and a damping plug (62) is also arranged in the front end of the valve core (63).
2. The compact load sensitive valve of claim 1, wherein: the front end of the thread insert (611) is provided with a radial semicircular hole (612).
3. The compact load sensitive valve of claim 1, wherein: a first P cavity (613) is arranged between the front ends of the valve core (63) and the valve sleeve (64) and the pump power valve body (61); and a second P cavity (614) is arranged between the tail ends of the valve sleeve (64) and the valve core (63) and the front end of the threaded sleeve (611) and the valve body (61) of the pump power valve.
4. The compact load sensitive valve of claim 3, wherein: a cavity A (615), a cavity B (616), a cavity T (617) and a cavity X (618) are sequentially arranged in the pump power valve body (61) from front to back; the cavity A (615) is matched with an oil outlet of the pump (1), the cavity B (616) is communicated with an oil port of a rodless cavity of the variable piston (2), and the cavity T (617) is communicated with an oil return cavity; the X cavity (618) is communicated with an oil outlet of the pump (1) through a throttle valve (4).
5. The compact load sensitive valve of claim 4, wherein: the X cavity (618) corresponds in position to the second P cavity (614).
6. The compact load sensitive valve of claim 1, wherein: the valve sleeve (64) comprises a valve sleeve body (641), and a radial A hole (642), a radial B hole (643) and a radial T hole (644) are sequentially arranged on the valve sleeve body (641) from front to back; an annular groove (645) is formed in the inner wall surface of the radial hole B (643); the tail end of the valve sleeve body (641) is provided with a limiting step (646) matched with the valve body (61) of the pump power valve.
7. The compact load sensitive valve of claim 6, wherein: the valve core (63) comprises a valve core body (631), an axial c cavity (632) is arranged at the front end of the valve core body (631), and a radial a hole (633) matched with the axial c cavity (632) is formed in the valve core body (631); the middle part of the valve core body (631) is provided with an annular control step (634); the annular control step (634) mates with the annular groove (645).
8. The compact load sensitive valve of claim 7, wherein: inclined chamfers (635) are further arranged at two ends of the annular control step (634).
CN202121877231.2U 2021-08-12 2021-08-12 Compact structure type load sensitive valve Active CN215830837U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202121877231.2U CN215830837U (en) 2021-08-12 2021-08-12 Compact structure type load sensitive valve

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202121877231.2U CN215830837U (en) 2021-08-12 2021-08-12 Compact structure type load sensitive valve

Publications (1)

Publication Number Publication Date
CN215830837U true CN215830837U (en) 2022-02-15

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ID=80194634

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202121877231.2U Active CN215830837U (en) 2021-08-12 2021-08-12 Compact structure type load sensitive valve

Country Status (1)

Country Link
CN (1) CN215830837U (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113623284A (en) * 2021-08-12 2021-11-09 力源液压(苏州)有限公司 Compact structure type load sensitive valve

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113623284A (en) * 2021-08-12 2021-11-09 力源液压(苏州)有限公司 Compact structure type load sensitive valve
CN113623284B (en) * 2021-08-12 2024-02-13 苏州力源液压有限公司 Compact structure type load sensitive valve

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Address after: 29 Caohu Avenue, Xiangcheng District, Suzhou, Jiangsu Province

Patentee after: Suzhou Liyuan Hydraulic Co.,Ltd.

Address before: 29 Caohu Avenue, Xiangcheng District, Suzhou, Jiangsu Province

Patentee before: LIYUAN HYDRAULIC (SUZHOU) Co.,Ltd.

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