CN112145495A - Hydraulic distributor with stop valve function - Google Patents

Abstract

The invention discloses a hydraulic distributor with a shut-off valve function, comprising: a valve body, the valve body is provided with a valve stem cavity, a limit shaft cavity and a cut-off valve cavity, and a valve stem is slidably arranged in the valve stem cavity , a limit shaft is slidably arranged in the limit shaft cavity, a cut-off valve is arranged in the cut-off valve cavity; the limit shaft is provided with an annular groove, and the limit shaft cavity and the cut-off valve cavity meet There is a hydraulic control oil port that communicates with the pressure oil port; the end of the valve core of the stop valve is provided with a boss, and the boss corresponds to the position of the annular groove of the limit shaft; the valve stem One end of the valve stem is provided with a valve stem groove, the valve stem groove is provided with an outer end surface and an inner end surface, the limit shaft is fixedly connected with a fork, and the shift fork is sleeved in the valve stem groove . When the hydraulic control distributor is in the ascending, descending and floating working positions, the globe valve can be automatically opened and maintained without the need for an electric control system and a linear actuator, and the structure is simple.

Description

Hydraulic distributor with shut-off valve function

technical field

The present invention relates to the technical field of hydraulic suspension devices, in particular to a hydraulic distributor with a shut-off valve function.

Background technique

The hydraulic suspension device of agricultural equipment (such as tractors) is used to hook up hanging or semi-suspension agricultural implements, carry out the lifting and lowering of agricultural implements and adjust the tillage depth, and realize loading and hydraulic power output, etc. The hydraulic suspension device consists of a hydraulic system and a suspension mechanism. The hydraulic system includes an oil pump, a distributor, a lifting cylinder, and an oil cylinder control mechanism. The suspension mechanism includes an upper pull rod, a pull down rod, and a lifting arm. On the one hand, by manipulating the distributor, the agricultural implement can be raised, lowered, neutral and floating, so that the tractor has the functions of position control, force control and force-position comprehensive control. Realize active shock absorption of agricultural implements.

During use, it was found that when the hydraulic distributor is in the neutral working mode, the force of the agricultural implement acting on the lifting cylinder forms a high pressure on the hydraulic oil, which is transmitted to the hydraulic distributor and leaks through the gap between the valve body and the valve stem in the hydraulic distributor. , resulting in subsidence of farm implements.

In order to solve the above technical problems, the applicant of the present invention discloses a shut-off valve of a hydraulic suspension device in Chinese invention patent application CN202011001404.4, and discloses an intelligent control of a hydraulic suspension device in Chinese invention patent application CN202011003075.7 The system, in the Chinese invention patent application CN202011001409.7, discloses a hydraulic distributor of a hydraulic suspension device. In the above three patent applications, the shut-off valve is arranged in the rodless cavity of the lifting cylinder of the hydraulic suspension device and the hydraulic suspension. Between the first working oil ports of the hydraulic distributor of the device. When the hydraulic distributor is in a neutral state, the shut-off valve is closed under the elastic force of the return spring, which cuts off the connection between the rodless chamber of the lifting cylinder and the hydraulic distributor, and avoids the settlement of the agricultural implement caused by the leakage of the hydraulic distributor. Since the valve core of the globe valve includes a first valve core segment and a second valve core segment with the same outer diameter, an annular groove is provided between the first valve core segment and the second valve core segment, and the annular groove is connected to the second valve core segment. The position of the first cavity of the first valve sleeve corresponds to the position, the first valve core segment is slidably matched with the first valve sleeve, the second valve core segment is slidably matched with the second valve sleeve, and the The second valve core sleeve is provided with a flange near the annular groove, the flange is provided with a valve core sealing cone surface, the end of the first valve sleeve is provided with a valve sleeve sealing cone surface, and the valve core is provided with a valve core sealing cone surface. The taper of the sealing cone surface and the sealing cone surface of the valve sleeve are different. Under the action of the return spring, when the sealing cone surface of the valve core is pressed against the inner edge of the sealing cone surface of the valve sleeve, the hydraulic oil can It is filled to the inner edge of the sealing cone surface of the valve sleeve, so that the first cavity is disconnected from the second cavity. The inner diameter of the sleeve and the second valve sleeve are also the same. Therefore, in the first chamber, the force of the hydraulic oil on the valve core is zero, and in the second chamber, the force of the hydraulic oil on the valve core is also zero. , In this way, to open the valve only need to overcome the elastic force of the return spring, completely unaffected by the hydraulic oil flowing through the valve, the operation is more sensitive and the use is more reliable.

It is very convenient to control the shut-off valve with the hydraulic system of the hydraulic suspension device. In the above technical solution, the free end opening of the first valve sleeve is a hydraulic control port, the hydraulic control port is communicated with the main oil circuit of the hydraulic suspension device, and the preset elastic force of the return spring is greater than The thrust of the oil pressure on the valve core when the main oil circuit is in a pressure relief state is smaller than the thrust on the valve core when the main oil circuit is in a high pressure state. When the hydraulic distributor is in the rising working position and When the working position is lowered, the main oil circuit of the hydraulic suspension device is in a high pressure state, and the valve core can overcome the elastic force of the return spring under the action of the high pressure oil, so that the shut-off valve is opened.

However, when the hydraulic distributor is in the floating working position, the main oil circuit of the hydraulic suspension device is in an unloaded state, and its oil pressure is not enough to overcome the elastic force of the return spring. In order to ensure that the stop valve can also be opened in this state, The electric control system must be used to control the linear actuator to exert an axial force on the globe valve spool, so the control system of the hydraulic control valve will become more complicated.

SUMMARY OF THE INVENTION

In view of the above deficiencies of the prior art, the present invention provides a hydraulic distributor with the function of a stop valve. When the hydraulic control distributor is in the ascending, descending and floating working positions, the stop valve can be operated without an electric control system and a linear actuator. Automatic opening and maintaining, simple structure.

In order to solve the above-mentioned technical problems, the technical scheme adopted in the present invention is:

A hydraulic distributor with a shut-off valve function, comprising: a valve body, a valve stem cavity is opened in the valve body, a valve stem is slidably arranged in the valve stem cavity, the valve stem penetrates the valve stem cavity, and the The valve stem cavity is provided with a first working oil cavity communicated with the first working oil port, a second working oil cavity communicated with the second working oil port, a pressure oil cavity communicated with the pressure oil port, and a pressure oil cavity communicated with the oil return port. In the oil return cavity, one side of the valve body is provided with a sealing end cover; one end of the valve rod is connected with a hydraulic push rod, and a valve rod return spring is provided between the other end and the sealing end cover; Under the combined action of the hydraulic push rod and the valve rod return spring, when the valve rod is located in different axial positions, the hydraulic distributor is respectively in the ascending working position, the neutral working position, the descending working position and the floating working position; when When the valve stem moves from left to right, the hydraulic distributor is in an ascending working position, a neutral working position, a descending working position and a floating working position in sequence.

The valve body is provided with a limit shaft cavity and a cut-off valve cavity, the limit shaft cavity is arranged in parallel with the valve stem cavity, and the limit shaft cavity is vertically communicated with the cut-off valve cavity; the limit shaft cavity A limit shaft is slid inside, and one end of the limit shaft is pressed against a limit shaft return spring arranged in the limit shaft cavity. Under the action of the limit shaft return spring, the limit shaft The other end of the shaft abuts against the sealing end cover, the elastic force of the return spring of the limit shaft is smaller than the elastic force of the valve stem return spring, the limit shaft is provided with an annular groove, and the limit shaft cavity A hydraulic control oil port communicated with the pressure oil port is opened at the intersection with the cut-off valve cavity; a cut-off valve is arranged in the cut-off valve cavity, and the cut-off valve includes a valve sleeve, a valve core, and a valve core return spring and sealing gland, the spring force of the return spring of the valve core is greater than the axial thrust of the hydraulic oil to the valve core in the neutral working position, the cut-off valve cavity is provided with a first oil passage groove and a second oil passage groove, the valve sleeve A first oil port and a second oil port are provided, the first oil port is communicated with the first oil passage groove, the second oil port is communicated with the second oil passage groove, and the sealing gland is threadedly connected to the The open end of the cut-off valve cavity presses and fixes the valve sleeve in the cut-off valve cavity, and the valve core return spring is located in the valve sleeve and is axially clamped between the sealing gland and the sealing gland. Between the valve cores, the end of the valve core is provided with a boss, and the boss corresponds to the position of the annular groove of the limit shaft; the valve stem is located on the valve stem return spring The end of one side is provided with a valve stem groove, the valve stem groove is provided with an outer end surface and an inner end surface, the limit shaft is fixedly connected with a shifting fork, and the shifting fork is sleeved on the valve stem groove When the hydraulic distributor is in the neutral working position and one end of the limiting shaft is abutting against the sealing end cover, the distance from the outer end face of the shift fork to the outer end face of the valve stem groove is greater than or equal to the distance that the valve stem moves from the neutral working position to the descending working position, but less than the distance that the valve stem moves from the neutral working position to the floating working position, the inner side of the fork The distance from the end face to the inner end face of the valve stem groove is greater than or equal to the distance that the valve stem moves from the neutral working position to the rising working position, and the distance from the inner end face of the shift fork to the end face of the valve body greater than or equal to the distance that the valve stem moves from the neutral working position to the floating working position; when the pressure oil port is in an unloaded state and the position of the boss is facing the annular groove, the The boss falls into the annular groove, the first oil port is disconnected from the second oil port under the action of the valve core return spring, and the shut-off valve is closed; when the pressure oil port When in a high pressure state, the valve core is lifted up, the boss is separated from the annular groove, the first oil port is communicated with the second oil port, and the stop valve is opened; when the pressure oil When the port is in an unloaded state and the position of the limit shaft staggers the position of the annular groove and the boss under the action of the shifting fork, the limit shaft restricts the boss from falling into the annular a groove, the first oil port is communicated with the second oil port, and the shut-off valve is opened.

Wherein, the valve sleeve includes a first valve sleeve and a second valve sleeve, the valve core return spring is located in the second valve sleeve; the first valve sleeve is provided with a connection with the first oil port a first cavity, the second valve sleeve is provided with a second cavity communicating with the second oil port; the valve core includes a first valve core segment and a second valve core segment with the same outer diameter, the first valve core segment A valve core annular groove is arranged between the valve core segment and the second valve core segment, the valve core annular groove corresponds to the position of the first cavity, and the first valve core segment and the first valve sleeve sliding fit, the second valve core segment is slidingly matched with the second valve sleeve, the second valve core segment is provided with a flange near the valve core annular groove, and the flange is provided with a valve core seal A cone surface, the end of the first valve sleeve is provided with a valve sleeve sealing cone surface, the valve core sealing cone surface and the valve sleeve sealing cone surface have different tapers, under the action of the valve core return spring, When the sealing cone surface of the valve core abuts against the inner edge of the sealing cone surface of the valve sleeve, the communication between the first cavity and the second cavity is disconnected.

Wherein, the first oil passage is communicated with the first working oil port of the hydraulic distributor, and the second oil passage is communicated with the rodless cavity of the lift cylinder of the hydraulic suspension device. or

The communication relationship between the first oil channel and the second oil channel is reversed, that is, the first oil channel is communicated with the rodless cavity of the lift cylinder, and the second oil channel is connected to the first oil channel of the hydraulic distributor. A working oil port is connected.

Wherein, the valve stem is a hollow valve stem, and the valve stem return spring is arranged in the hollow cavity of the hollow valve stem.

After adopting the above-mentioned technical scheme, the technical effect achieved by the present invention is:

1. When the hydraulic distributor is in the neutral working position, the pressure oil port is in an unloaded state and the boss is facing the annular groove, and the boss is under the action of the valve core return spring. falling into the annular groove, the first oil port is disconnected from the second oil port, and the shut-off valve is closed; when the hydraulic distributor is in the ascending working position or the descending working position, the pressure oil The port is in a high pressure state, the limit shaft is located in the neutral working position of the valve stem, the valve core is lifted up, the boss is separated from the annular groove, and the first oil port is connected to the The second oil port is connected, and the shut-off valve is opened; in the process of moving the valve stem from the descending working position to the floating working position, on the premise that the valve core is lifted, the valve stem Drive the shift fork to move the limit shaft to the right (the direction shown in the figure), and when the floating working position is reached, the pressure oil port is in an unloaded state. At this time, the annular groove and the convex The position of the platform is staggered, the limit shaft restricts the boss from falling into the annular groove, the first oil port is communicated with the second oil port, and the stop valve is opened; when the floating state is ended, it is necessary to When returning to the neutral/up/down working position, the electronic control system firstly controls the leftward movement of the valve stem through the hydraulic push rod. At this time, the return spring of the limit shaft may not be enough to overcome the shut-off valve. The friction between the core and the limit shaft, the limit shaft does not move, and continues to control the valve stem to move to the left (the direction shown in the figure) to the descending working position, the pressure oil port is in a high pressure state, pushing the cut-off The valve spool moves upwards and disengages from the annular groove of the limit shaft, and the limit shaft will move to the left to the neutral working position under the action of the return spring of the limit shaft. It can be seen from the above that when the hydraulic control distributor is in the neutral working position, the globe valve will automatically close, and when the hydraulic control distributor is in the ascending, descending and floating working positions, the globe valve can be automatically Open and hold, simple structure.

2. In the neutral state of the present invention, the shut-off valve is closed under the elastic force of the spool return spring, which cuts off the connection between the rodless chamber of the lifting cylinder and the hydraulic distributor, and avoids the settlement of farm implements caused by the leakage of the hydraulic distributor. Since the valve core of the globe valve of the present invention includes a first valve core segment and a second valve core segment with the same outer diameter, an annular groove is provided between the first valve core segment and the second valve core segment, and the annular groove is formed between the first valve core segment and the second valve core segment. The groove corresponds to the position of the first cavity of the first valve sleeve, the first valve core segment is slidably matched with the first valve sleeve, the second valve core segment is slidably matched with the second valve sleeve, The second valve core sleeve is provided with a flange near the annular groove, the flange is provided with a valve core sealing cone surface, the end of the first valve sleeve is provided with a valve sleeve sealing cone surface, the The taper of the sealing cone surface of the valve core is different from that of the sealing cone surface of the valve sleeve. Under the action of the return spring, when the sealing cone surface of the valve core is pressed against the inner edge of the sealing cone surface of the valve sleeve, the hydraulic pressure Oil can be filled to the inner edge of the sealing cone surface of the valve sleeve, so that the first cavity is disconnected from the second cavity. The inner diameter of the first valve sleeve and the second valve sleeve are also the same. Therefore, in the first chamber, the force of the hydraulic oil on the valve core is zero, and in the second chamber, the force of the hydraulic oil on the valve core is also In this way, the valve only needs to overcome the elastic force of the return spring to open the valve, and it is completely unaffected by the hydraulic oil flowing through the valve, and the operation is more sensitive and the use is more reliable.

Description of drawings

1 is a cross-sectional view of a valve stem and a limit shaft located on the same section of an embodiment of a hydraulic distributor with a shut-off valve function of the present invention;

Fig. 2 is the front view of the shift fork in the embodiment shown in Fig. 1;

Fig. 3 is the longitudinal sectional view of the limit shaft in the embodiment shown in Fig. 1;

4 is a structural cross-sectional view of the working state when the stop valve and the limit shaft are located in the same section when the hydraulic distributor is in the neutral working position in the embodiment shown in FIG. 1;

Fig. 5 is the longitudinal sectional view of the shut-off valve in Fig. 4;

Fig. 6 is a partial enlarged view at I in Fig. 5;

Fig. 7 is the longitudinal sectional view of the valve core in Fig. 5;

8 is a sectional view of the working state structure when the hydraulic distributor is in the descending working position or the ascending working position in the embodiment shown in FIG. 1 ;

Fig. 9 is a structural cross-sectional view of the working state when the hydraulic distributor is in the floating working position in the embodiment shown in Fig. 1 ;

In the picture:

100- valve body, 101- valve stem, 102- valve stem groove, 103- valve stem return spring, 104- sealing end cover, 105- first oil passage, 106- second oil passage, 107- hydraulic control oil port , 108-hydraulic push rod;

200-limit shaft, 201-annular groove, 202-limit shaft return spring, 203-shift fork;

301-First valve sleeve, 3011-Valve sleeve sealing cone, 301a-First chamber, 301A-First oil port, 302-Second valve sleeve, 302b-Second chamber, 302B-Second oil port, 303- Sealing gland, 304-return spring, 305-spool, 3051-first spool segment, 3052-second spool segment, 3053-flange, 3053A-spool sealing cone, 3054-spool annular groove , 3055 - boss, d - outer diameter, α - the angle difference between the sealing cone surface of the valve core and the sealing cone surface of the valve core;

a- the first working oil chamber, b- the second working oil chamber, p- pressure oil chamber, t- oil return chamber;

S1 - the distance from the outer end face of the shift fork to the outer end face of the valve stem groove, S2 - the distance from the inner end face of the shift fork to the inner end face of the valve stem groove, and S3 - the distance from the inner end face of the shift fork to the end face of the valve body.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

As shown in Figures 1 to 3, a hydraulic distributor with a shut-off valve function, the valve body 100 is provided with a valve stem cavity, the valve stem cavity is slidably provided with a valve stem 101, and the valve stem 101 penetrates the valve stem cavity, so The hydraulic distributor is provided with a first working oil port, a second working oil port, a pressure oil port and an oil return port, and the valve stem cavity is provided with a first working oil cavity a, which is communicated with the first working oil port. A second working oil chamber b communicated with the second working oil port, a pressure oil chamber p communicated with the pressure oil port, and an oil return chamber t communicated with the oil return port. One side of the valve body 100 is provided with a sealing end cover 104, one end of the valve stem 101 is connected with a hydraulic push rod 108, and a valve stem return spring 103 is provided between the other end and the sealing end cover 104. Preferably, the valve stem 101 is The hollow valve stem, the valve stem return spring 103 is arranged in the hollow cavity of the hollow valve stem. Under the combined action of the hydraulic push rod 108 and the valve stem return spring 103, when the valve stem 101 is located at different axial positions, the hydraulic distributors are respectively at different working positions; in this embodiment, when the valve stem 101 is automatically When moving from left to right, the hydraulic distributor is in the ascending working position, the neutral working position, the descending working position and the floating working position in sequence.

As shown in FIGS. 4 to 7 , the valve body 100 is provided with a limit shaft cavity and a cut-off valve cavity, the limit shaft cavity is arranged in parallel with the valve stem cavity, and the limit shaft cavity is in vertical communication with the cut-off valve cavity. .

A limit shaft 200 is slidably arranged in the limit shaft cavity, and one end of the limit shaft 200 is pressed against a limit shaft return spring 200 arranged in the limit shaft cavity. The other end of the limit shaft 200 abuts against the sealing end cover 104, the elastic force of the return spring of the limit shaft is smaller than that of the valve stem return spring, the limit shaft 200 is provided with an annular groove 201, and the limit shaft 200 is provided with an annular groove 201. A hydraulic control oil port 107 communicated with the pressure oil port is opened at the intersection of the position shaft cavity and the cut-off valve cavity, and the hydraulic oil introduced from the pressure oil port acts on the bottom of the valve core 305 .

The shut-off valve cavity is provided with a shut-off valve. The shut-off valve includes a valve sleeve, a valve core 305, a valve core return spring 304 and a sealing gland 303. The spring force of the valve core return spring is greater than the hydraulic pressure at the neutral working position. The axial thrust of the oil on the valve core 305, the cut-off valve cavity is provided with a first oil channel 105 and a second oil channel 106, the valve sleeve is provided with a first oil port 301A and a second oil port 302B, the first oil The port 301A is communicated with the first oil passage 105, the second oil port is communicated with the second oil passage 106 of 302B, and the sealing gland 303 is threadedly connected to the open end of the shut-off valve cavity to squeeze and fix the valve sleeve to the In the cut-off valve cavity, the valve core return spring 304 is located in the valve sleeve and is axially clamped between the sealing gland 303 and the valve core 305. The end of the valve core 305 is provided with a boss 3055. The positions of the annular grooves 201 of the limiting shaft correspond to each other.

5 to 7 show the detailed structure of the shut-off valve. The valve sleeve includes a first valve sleeve 301 and a second valve sleeve 302. By screwing the sealing gland 303, the first valve sleeve 301 and the second valve sleeve 302 can be axially arranged and squeezed and fixed in the cut-off valve cavity. . The valve core return spring 304 is located in the second valve sleeve 302; the first valve sleeve 301 is provided with a first cavity 301a communicating with the first oil port 301A, and the second valve sleeve 302 is provided with a second oil port 302B communicates with the second cavity 302b.

The valve core 305 includes a first valve core segment 3051 and a second valve core segment 3052 with the same outer diameter, a valve core annular groove 3054 is provided between the first valve core segment 3051 and the second valve core segment 3052, and the valve core annular groove 3054 Corresponding to the position of the first cavity 301a, the first valve core segment 3051 is slidingly matched with the first valve sleeve 301, the second valve core segment 3052 is slidingly matched with the second valve sleeve 302, and the second valve core segment 3052 is close to the valve. The core annular groove 3054 is provided with a flange 3053, the flange 3053 is provided with a valve core sealing cone surface 3053A, the end of the first valve sleeve 301 is provided with a valve sleeve sealing cone surface 3011, the valve core sealing cone surface 3053A and the valve The taper of the sleeve sealing cone surface is different and has an angle difference α. Under the action of the valve core return spring 304, when the valve core sealing cone surface 3053A abuts against the inner edge of the valve sleeve sealing cone surface 3011, the first cavity 301a is connected to the second cavity 301a. Cavity 302b is disconnected.

In the present invention, the taper of the valve core sealing cone surface 3053A and the valve sleeve sealing cone surface 3011 are different. Under the action of the valve core return spring 304, the valve core sealing cone surface 3053A abuts against the inner side of the valve sleeve sealing cone surface 3011 At the edge, the hydraulic oil can be filled to the inner edge of the sealing cone surface 3011 of the valve sleeve, so that the first cavity 301a and the second cavity 302b are disconnected from communication. The outer diameter d of the first valve core segment 3051 and the first valve sleeve 301 are slidingly matched, and the second valve core segment 3052 interacts with the second valve sleeve 302, the outer diameter d of the first valve core segment 3051 is the same as the first valve core segment 3051. The inner diameter of a valve sleeve 301 is the same, and the outer diameter d of the second valve core segment 3052 is also the same as the inner diameter of the second valve sleeve 302. Therefore, in the first cavity 301a, the force of the hydraulic oil on the valve core 305 is: Zero, in the second chamber 302b, the force of the hydraulic oil on the spool 305 is also zero. In this way, to open the valve, it only needs to overcome the elastic force of the return spring of the spool, and is not affected by the hydraulic oil flowing through the valve. impact, handling is more sensitive, and the use is more reliable.

As shown in FIG. 1, the end of the valve stem 101 on the side of the valve stem return spring 103 is provided with a valve stem groove 102, and the valve stem groove 102 is provided with an outer end face and an inner end face (the right side is the outer side, the left side is the outer side). A shift fork 203 is fixedly connected to the limit shaft 200. The shift fork 203 is sleeved in the valve stem groove 102. When the valve stem 101 moves axially, the inner/outer end face of the valve stem groove 102 will pass the shift fork. 203 drives the limit shaft 200 to move.

As shown in FIG. 1 , when the hydraulic distributor is in the neutral working position and one end of the limiting shaft 200 abuts against the sealing end cover 104 , the distance S1 from the outer end face of the shift fork 203 to the outer end face of the valve stem groove 102 is greater than or equal to the distance that the valve stem 101 moves from the neutral working position to the descending working position but is less than the distance that the valve stem 101 moves from the neutral working position to the floating working position, so that when the valve stem 101 moves from the When the neutral working position moves to the descending working position, the limiting shaft 200 does not move. The distance S2 from the inner end face of the shift fork 203 to the inner end face of the valve stem groove 102 is greater than or equal to the distance S2 that the valve stem 101 moves from the neutral working position to the rising working position. In this way, when the valve stem 101 works from the neutral position When the position moves to the left to the ascending working position, the limiting shaft 200 does not move. The distance S3 from the inner end face of the fork 203 to the end face of the valve body 100 is greater than or equal to the distance that the valve stem 101 moves from the neutral working position to the floating working position. In this way, when the valve stem 101 moves from the neutral working position to the right When moving to the floating working position, the shift fork will not interfere with the valve body 100 .

As shown in FIG. 4 , when the hydraulic distributor is in the neutral working position, the pressure oil port is in an unloaded state and the position of the boss 3055 is facing the annular groove 210 , and the boss 3055 is under the action of the valve core return spring 304 Falling into the annular groove 201, the first oil port 301A is disconnected from the second oil port 302B, and the shut-off valve is closed.

As shown in FIG. 8 , when the hydraulic distributor is in the ascending working position or the descending working position, the pressure oil port is in a high-pressure state, the limit shaft 200 remains at the neutral working position, and the valve core 305 is lifted up. , the boss 3055 is separated from the annular groove 201 , the first oil port 301A is communicated with the second oil port 302B, and the shut-off valve is opened.

As shown in FIG. 1 and FIG. 9 , in the process of moving the valve stem 101 from the descending working position to the floating working position, on the premise that the valve core 305 is lifted up, the valve stem 101 drives the shift fork 203 to limit the The position shaft 200 moves to the right (the direction shown in the figure), and when reaching the floating working position, the pressure oil port is in an unloaded state. At this time, the positions of the annular groove 201 and the boss 3055 are staggered, and the limit shaft 200 limits The boss 3055 falls into the annular groove 201, the first oil port 301A communicates with the second oil port 302B, and the shut-off valve is opened.

When the floating state ends and needs to return to the neutral/up/down working position, the electronic control system first controls the valve stem 101 to move to the left through the hydraulic push rod 108. The friction force between the stop valve spool 305 and the limit shaft 200, the limit shaft 200 does not move, and when the valve stem 101 continues to move to the left (in the direction shown in the figure) to the descending working position, the pressure oil port is in a high pressure state , push the stop valve spool 305 to move upward, and disengage from the limit shaft 200, the limit shaft 200 will move left to the neutral working position under the action of the limit shaft return spring 202 (that is, as shown in FIG. 4 or FIG. 8 ). Location). It can be seen from the above that when the hydraulic control distributor is in the neutral working position, the globe valve will automatically close, and when the hydraulic control distributor is in the ascending, descending and floating working positions, the globe valve can be automatically Open and hold, simple structure.

When the hydraulic distributor disclosed in the present invention is applied to the hydraulic suspension device of agricultural equipment such as tractors, the first oil passage 105 of the shut-off valve cavity is communicated with the first working oil port of the hydraulic distributor, and the second oil passage 106 is connected to the first working oil port of the hydraulic distributor. The rodless chambers of the lift cylinders of the hydraulic suspension device communicate with each other. Or the communication relationship between the first oil passage 105 and the second oil passage 106 is reversed, that is, the first oil passage 105 is communicated with the rodless cavity of the lift cylinder, and the second oil passage 106 is connected with the first working of the hydraulic distributor. Port is connected.

In the hydraulic distributor disclosed in the present invention, when the valve stem 101 moves from left to right, the working positions it can provide are not limited to the ascending working position, the neutral working position, the descending working position and the floating working position. Active damping is performed on the attached farm equipment during field operations, and with the damping system, a damping work position can also be set. In the floating state, neutral state, but the farm implement has been on the ground for a long time or in the shutdown state, etc., the accumulator cannot be charged, which may cause the pressure in the accumulator to be very low or even zero. At this time, the electronic control unit can only control the valve. The stem moves to the right as shown in the drawing, and the stem cannot be controlled to move to the left. In order to achieve the purpose of controlling the bidirectional movement of the valve stem of the hydraulic distributor under these special working conditions, a neutral charging working position and a floating charging working position can also be set. Generally speaking, only the neutral working position and the shock-absorbing working position have the problem of oil leakage, and the stop valve needs to be closed. When it is in other working positions, the stop valve can be kept open. According to the principle introduced above, by setting the relative The position and the specific displacement of the movement of the valve stem 101 can be achieved, which will not be repeated here.

The present invention is not limited to the above-mentioned embodiments, and all improvements made based on the concept, principle, structure and method of the present invention will fall within the protection scope of the present invention.

Claims (5)

1. A hydraulic distributor with a shut-off valve function, comprising: A valve body, the valve body is provided with a valve stem cavity, a valve stem is slidably arranged in the valve stem cavity, the valve stem penetrates the valve stem cavity, and the valve stem cavity is provided with a first working oil port. The first working oil cavity (a), the second working oil cavity (b) communicated with the second working oil port, the pressure oil cavity (p) communicated with the pressure oil port, and the return oil cavity ( t), one side of the valve body is provided with a sealing end cover; one end of the valve rod is connected with a hydraulic push rod, and a valve rod return spring is provided between the other end and the sealing end cover; Under the combined action of the push rod and the valve rod return spring, when the valve rod is in different axial positions, the hydraulic distributor is in the ascending working position, the neutral working position, the descending working position and the floating working position, respectively. When the valve rod moves from left to right, the hydraulic distributor is in the ascending working position, the neutral working position, the descending working position and the floating working position in sequence; it is characterized in that, The valve body is provided with a limit shaft cavity and a cut-off valve cavity, the limit shaft cavity is arranged in parallel with the valve stem cavity, and the limit shaft cavity is in vertical communication with the cut-off valve cavity; A limit shaft is slidably arranged in the limit shaft cavity, and one end of the limit shaft is pressed against a limit shaft return spring arranged in the limit shaft cavity, and under the action of the limit shaft return spring The other end of the limit shaft is pressed against the sealing end cover, the elastic force of the return spring of the limit shaft is smaller than that of the valve stem return spring, and the limit shaft is provided with an annular groove, A hydraulic control oil port communicated with the pressure oil port is opened at the intersection of the limit shaft cavity and the cut-off valve cavity; The shut-off valve cavity is provided with a shut-off valve, and the shut-off valve includes a valve sleeve, a valve core, a valve core return spring and a sealing gland, and the spring force of the valve core return spring is greater than that of the hydraulic oil in the neutral working position For the axial thrust of the valve core, the cut-off valve cavity is provided with a first oil passage groove and a second oil passage groove, the valve sleeve is provided with a first oil port and a second oil port, and the first oil port is provided with the first oil port and the second oil port. The first oil passage is in communication with the second oil passage, and the second oil port is in communication with the second oil passage. In the shut-off valve cavity, the valve core return spring is located in the valve sleeve and is axially clamped between the sealing gland and the valve core, and the end of the valve core is provided with a boss, The boss is corresponding to the position of the annular groove of the limiting shaft; The end of the valve stem located on one side of the valve stem return spring is provided with a valve stem groove, the valve stem groove is provided with an outer end face and an inner end face, and the limit shaft is fixedly connected with a fork, The shift fork is sleeved in the valve stem groove; when the hydraulic distributor is in a neutral working position and one end of the limit shaft is pressed against the sealing end cover, the outer side of the shift fork The distance (S1) from the end face to the outer end face of the valve stem groove is greater than or equal to the distance that the valve stem moves from the neutral working position to the descending working position, but is smaller than the valve stem from the neutral working position The distance from moving to the floating working position, the distance (S2) from the inner end face of the fork to the inner end face of the valve stem groove is greater than or equal to the movement of the valve stem from the neutral working position to the ascending working position The distance from the inner end face of the fork to the end face of the valve body (S3) is greater than or equal to the distance that the valve stem moves from the neutral working position to the floating working position; When the pressure oil port is in an unloaded state and the boss is facing the annular groove, the boss falls into the annular groove, and under the action of the valve core return spring, the The first oil port is disconnected from the second oil port to close the shut-off valve; when the pressure oil port is in a high pressure state, the valve core is lifted up, and the boss is separated from the annular groove , the first oil port is communicated with the second oil port, and the shut-off valve is opened; when the pressure oil port is in an unloaded state and the limit shaft makes the annular When the position of the groove and the boss is staggered, the limiting shaft restricts the boss from falling into the annular groove, the first oil port is communicated with the second oil port, and the stop valve is opened . 2. The hydraulic distributor with shut-off valve function according to claim 1, characterized in that, The valve sleeve includes a first valve sleeve and a second valve sleeve, the valve core return spring is located in the second valve sleeve; the first valve sleeve is provided with a first valve sleeve communicating with the first oil port a cavity, the second valve sleeve is provided with a second cavity communicating with the second oil port; The valve core includes a first valve core segment and a second valve core segment with the same outer diameter, a valve core annular groove is arranged between the first valve core segment and the second valve core segment, and the valve core is annular The groove corresponds to the position of the first cavity, the first valve core segment is slidably matched with the first valve sleeve, the second valve core segment is slidably matched with the second valve sleeve, and the second valve core segment is slidably matched with the second valve sleeve. The core segment is provided with a flange near the annular groove of the valve core, the flange is provided with a valve core sealing cone surface, the end of the first valve sleeve is provided with a valve sleeve sealing cone surface, and the valve core sealing The taper of the cone surface and the sealing cone surface of the valve sleeve is different. Under the action of the valve core return spring, when the valve core sealing cone surface abuts against the inner edge of the valve sleeve sealing cone surface, the The first cavity is disconnected from the second cavity. 3 . The hydraulic distributor with shut-off valve function according to claim 1 , wherein the first oil passage is communicated with the first working oil port of the hydraulic distributor, and the second oil passage is connected to the hydraulic pressure. 4 . The rodless chambers of the lift cylinders of the suspension device communicate with each other. 4 . The hydraulic distributor with a shut-off valve function according to claim 3 , wherein the communication relationship between the first oil passage groove and the second oil passage groove is reversed, that is, the first oil passage groove and the The rodless cavity of the lifting oil cylinder is communicated, and the second oil passage is communicated with the first working oil port of the hydraulic distributor. 5 . The hydraulic distributor with shut-off valve function according to claim 1 , wherein the valve stem is a hollow valve stem, and the valve stem return spring is arranged in the hollow cavity of the hollow valve stem. 6 .

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