KR20200060502A - Travel motor changeover valve, travel motor and civil machinery - Google Patents

Abstract

A travel motor shift valve (100), a travel motor and a construction machine are disclosed. The traveling motor switching valve 100 includes a valve core 1, a first working oil port Y, a second working oil port L, a third working oil port Z, and an external control oil port X. And a feedback oil port (C). The valve core 1 is switched from low speed to high speed and high speed to low speed at two different preset values so that the input pressure values of the motor 400 do not satisfy the switching boundary conditions after switching, thereby driving the motor Effectively prevents repetitive switching between high speed and low speed, and reduces the vibration of construction machinery under high load conditions.

Description

Travel motor changeover valve, travel motor and construction machinery

Related applications

The present invention is based on the Chinese application of application number 201711246964.4 filed on December 1, 2017, and claims its priority. The disclosure content of this Chinese application is incorporated herein in its entirety.

The present invention relates to the technical field of engineering machinery, specifically, to a travel motor shift valve, a travel motor, and a civil engineering machine.

Traveling motors are widely used in civil engineering machines such as excavators to drive civil engineering machines to drive. The traveling motor usually includes a motor and a swashplate control mechanism, and the swash plate control mechanism controls the rotation angle of the output shaft of the motor by controlling the angle of the swash plate of the motor, whereby the traveling motor has two speeds, high speed and low speed. It has a switching function. In the low speed mode, the output rotational speed of the traveling motor is low, but its displacement is large, and a larger torque can be output under the same input power, whereas in the high speed mode, the output rotational speed of the traveling motor is high but its displacement is small, A smaller torque can be output under the same input power.

When excavators and other civil engineering machines are driving in heavy loads such as ramps, muddy swamps, or towings, the drive motors are often required to provide greater drive torque, ie drive motors are required to operate in low speed mode. Required, whereby the driving motor provides greater torque to prevent the running from stopping or driving without force; When the driving resistance becomes smaller, the driving motor is required to switch from the low speed mode to the high speed mode to improve the driving efficiency. Therefore, it is desired that the travel motor enables switching between the high speed mode and the low speed mode.

In order to control the traveling motor to automatically switch from the high speed mode to the low speed mode under the high load condition, the traveling motor is equipped with a normal traveling motor switching valve. By controlling whether to supply high pressure oil to the inclined plate control mechanism, the traveling motor switching valve controls whether the traveling motor switches from a high speed mode to a low speed mode, thereby realizing an automatic switching function of the traveling motor.

However, the present inventors, in the prior art, whether the traveling motor switching valve generally supplies high pressure oil to the inclined plate control mechanism for controlling the switching by detecting whether the actual pressure of the motor exceeds a specific preset value at a high speed state. It was recognized that the decision was made. Since the maximum output provided by the driving force (engine) of a civil engineering machine is a constant value, the output torque of the traveling motor is proportional to the working pressure and displacement, and thus, under the same operating conditions, after the motor is switched from high speed to low speed, the motor The pressure of the input port will be lower than the pressure before switching, i.e., below the preset value, at which time the switching valve will automatically return to the high speed mode, whereby the traveling motor repeatedly between high speed and low speed under high load conditions. Switching, which causes the civil machine to vibrate under high load conditions, additionally affects the life and safety of the switching valve itself, the drive motor and the civil machine as a whole, as well as reducing the convenience of the product.

Therefore, the technical problem to be solved by the present invention is: to prevent the traveling motor from repeatedly switching between high speed and low speed, in order to reduce and reduce the vibration of the civil machine under high load conditions.

In order to solve the above technical problem, a travel motor shift valve provided according to the first aspect of the present invention includes a valve core, a first working oil port, and a second operation. An oil port, a third working oil port, an external control port and a feedback oil port, wherein the valve core has a first working position and a second working position; In a first operating position, the first working oil port is blocked and the second working oil port is in communication with the third working oil port; In a second working position, the first working oil port communicates with the third working oil port and the second working oil port is blocked; The first working oil port is for communication with an oil source, the second working oil port is for communication with an oil tank, and the third working oil port is for controlling the inclined plate of a travel motor. To communicate with a swashplate control mechanism; The externally controlled oil port is for guiding oil to act on the first axial end of the valve core so as to generate a tendency for the valve core to move from the first operating position to the second operating position, and the feedback The oil port is intended to feed back the working pressure of the motor of the traveling motor to the second axial end of the valve core so as to generate a tendency for the valve core to move from the second working position to the first working position;

The travel motor switching valve 100 is:

The valve core is configured to move from a first operating position to a second operating position when the oil pressure of the feedback oil port is less than a first preset value (P _C1 ), and the valve core is the feedback oil When the oil pressure of the port is greater than the second preset value (P _C2 ), it is configured to move from the second operating position to the first operating position, wherein the first preset value (P _C1 ) is the second Not equal to the preset value P _C2 ;

After the valve core is moved from the first operating position to the second operating position, the oil pressure of the feedback oil port is the first working value (P _C3 ), and the valve core is first from the second operating position. After switching to the operating position, the oil pressure of the feedback oil port is the second operating value (P _C4 ), and the relationship between the first operating value (P _C3 ) and the second preset value (P _C2 ) is P _C3 <K ₁ P _C2 , K ₁ ≤1, and the relationship between the second operating value P _C4 and the first preset value P _C1 is such that P _C4 > K ₂ P _C1 , K ₂ ≥1, It is composed.

In some embodiments, the travel motor switching valve further includes a first chamber, a second chamber, and a third chamber, the first chamber being in communication with the external control oil port, and the third chamber is the feedback oil The second working oil port and the first working oil port are in communication with the port, the second chamber being in communication with the third working oil port and the valve core moving from the first working position to the second working position. It is configured to be alternately switched in communication with, the effective pressure working area of the second chamber is smaller than the effective pressure working area of the third chamber.

In some embodiments, the travel motor changeover valve further comprises a spring, the spring being disposed at a second axial end of the valve core such that the valve core in the valve core is in a first operating position from a second operating position. Applying an acting force to generate a tendency to move to, the first preset value (P _C1 ) is P _C1 = (P _X × A ₁ -F ₁ ) / A ₃ , and the second The preset value (P _C2 ) is P _C2 = (P _X × A ₁ -F ₂ ) / (A ₃ -A ₂ ), and the first operating value (P _C3 ) is P _C3 = (V ₁ / V ₂ ) P _C1 , and the second operating value P _C4 is P _C4 = (V ₂ / V ₁ ) P _C2 , where P _X is the oil pressure of the external control oil port, A ₁ , A ₂ and A ₃ are effective pressure acting areas of the first chamber, the second chamber and the third chamber, respectively, F ₁ and F ₂ are the springs applied to the valve core at the first operating position and the second operating position, respectively. These are the acting forces, and V ₁ and V ₂ are the displacements of the motor at the first and second operating positions, respectively.

In some embodiments, the second chamber and the third chamber are disposed on the valve core, respectively, at the first axial end and the second axial end of the valve core.

In some embodiments, a first plunger chamber and a second plunger chamber are provided at the first axial end and the second axial end of the valve core, respectively; A first plunger is disposed inside the first plunger chamber, and a second plunger is disposed inside the second plunger chamber; The second chamber is located between the first plunger and the inner wall of the first plunger chamber, and the third chamber is located between the second plunger and the inner wall of the second plunger chamber.

In some embodiments, a first passage is disposed in the valve core, and the second chamber is in communication with one of the first working oil port and the second working oil port through the first passage; And / or a second passage in the valve core, the third chamber communicating with the feedback oil port through the second passage.

In some embodiments, the travel motor switching valve further comprises a first plugging piece disposed at a second axial end of the valve core; The spring of the travel motor switching valve abuts between the first stopper member and the second axial end of the valve core to generate a tendency for the valve core to move from the second operating position to the first operating position in the valve core. It is configured to exert an acting force to enable.

In some embodiments, a spring receiving chamber is provided on the surface of the first stopper member adjacent to the valve core, the spring being disposed inside the spring receiving chamber.

In some embodiments, a first through-hole is disposed in the first stopper member, and the first through-hole is in communication with the spring receiving chamber.

In some embodiments, a fastening groove is disposed on the surface of the first stopper member away from the valve core.

In some embodiments, a necking section is disposed at the first axial end of the valve core.

In some embodiments, a recess is disposed on the circumferential surface of the abdomen.

The second aspect of the present invention provides a traveling motor, the traveling motor includes a motor and a swashplate control mechanism connected to the inclined plate of the motor, and further includes a traveling motor switching valve of the present invention, The travel motor switching valve is disposed inside the shell of the motor.

In some embodiments, a second through-hole is disposed in the sheath, a valve core of the traveling motor changeover valve is disposed inside the second through-hole, and a first working oil port of the traveling motor changeover valve, The second working oil port, the third working oil port, the external control port and the feedback oil port are all disposed on the inner wall of the sheath.

The third aspect of the present invention further provides an engineering machinery comprising the traveling motor of the present invention.

Based on the improvement of the traveling motor switching valve, the valve core of the traveling motor switching valve is configured to switch from low speed to high speed and high speed to low speed at two different preset values, and the input pressure values of the motor after switching are By configuring both to not meet the switching boundary conditions, the present invention effectively prevents the traveling motor from repeatedly switching between high speed and low speed, and reduces the vibration of the construction machine under high load conditions.

Other features and advantages of the present invention will become apparent from the detailed description of the exemplary embodiment of the present invention with reference to the accompanying drawings below.

In order to more clearly show the technical solutions in the embodiments or the prior art of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly described below. Certainly, the drawings in the following description are only some of the specific embodiments of the present invention. Those skilled in the art will be able to obtain other drawings according to these drawings without any creative effort.
1 shows a hydraulic principle diagram of a traveling motor system according to an embodiment of the present invention.
FIG. 2 shows a sectional view showing the valve core of the travel motor switching valve of FIG. 1 in the first operating position.
FIG. 3 shows a sectional view showing the valve core of the travel motor switching valve shown in FIG. 1 in a second operating position.
4 shows a schematic view showing the structure of the valve core of FIGS. 2 and 3.

Now, technical solutions of the embodiments of the present invention will be more clearly and completely described with reference to the drawings of the embodiments of the present invention. Certainly, the described embodiments are only a part rather than all of the embodiments of the present invention. The description of at least one exemplary embodiment below is for illustration only, and is not intended as a limitation on the invention and on the application or use of the invention. All other embodiments obtained by those skilled in the art without any creative effort based on the embodiments of the present invention are included within the scope of the present invention.

Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies, methods and devices should be considered as part of the written specification.

In the description of the present invention, "forward, rear, up, down, left, right", "lateral, upright, vertical, horizontal" and "upper, lower," for convenience and simplicity of the description of the present invention only It should be understood that the direction or positional relationship indicated by words indicating a direction such as "is generally based on the direction or positional relationship shown in the drawings. Without the contrary, words indicating this direction are not intended to indicate or suggest that the associated device or component should have the specified direction or be constructed and operated in the specified direction, thus limiting the scope of protection of the present invention. It should not be understood as; The words "internal and external" refer to the inside and outside of the contour of each component itself.

In the description of the present invention, it should be understood that the use of words such as "first" and "second" to define elements is merely to facilitate differentiation between corresponding elements. Unless stated to the contrary, the words have no specific meaning and should not be construed as limiting the scope of protection of the present invention.

1-4 show an embodiment of the invention. Referring to Figure 1-4, the travel motor switching valve 100 provided by the present invention, the valve core (valve core) (1), the first working oil port (working oil port) (Y), the second operation It includes an oil port (L), a third working oil port (Z), an external control port (X) and a feedback oil port (C), wherein the valve core 1 has a first working position and a second working position. , In a first working position, the first working oil port (Y) is blocked and the second working oil port (L) is in communication with the third working oil port (Z), in a second working position, the first 1 working oil port (Y) is in communication with the third working oil port (Z) and the second working oil port (L) is blocked. The first working oil port (Y) is for communication with the oil supply source, the second working oil port (L) is for communication with the oil tank, and the third working oil port (Z) is for the driving motor To communicate with the swashplate control mechanism (500). The external control oil port X tends to guide the control oil to act on the first axial end of the valve core 1 so that the valve core 1 moves from the first operating position to the second operating position. It is intended to be able to generate. The feedback oil port C feedbacks the actual operating pressure of the motor 400 of the traveling motor to the second axial end of the valve core 1 so that the valve core 1 is removed from the second operating position. 1 To make it possible to generate a tendency to move to the operating position.

The travel motor switching valve 100 is configured as follows:

The valve core 1 is configured to move from a first operating position to a second operating position when the oil pressure of the feedback oil port C is less than a first preset value P _C1 , and the The valve core 1 is configured to move from the second operating position to the first operating position when the oil pressure of the feedback oil port C is greater than the second preset value P _C2 , and the first preset value (P _C1 ) is not the same as the second preset value P _C2 ;

After the valve core 1 is moved from the first operating position to the second operating position, the oil pressure of the feedback oil port C is a first operating value P _C3 , and the valve core 1 is a second After switching from the operating position to the first operating position, the oil pressure of the feedback oil port C is the second operating value P _C4 , where the first operating value P _C3 and the second preset value P _C2 ) Is P _C3 <K ₁ P _C2 , K ₁ ≤1, and the relationship between the second operating value (P _C4 ) and the first preset value (P _C1 ) is P _C4 > K ₂ P _C1 , K ₂ ≥1.

In the present invention, P _C1 and P _C2 are critical pressure values of the motor 400 with respect to the traveling motor switching valve 100 that controls the traveling motor to switch from low speed to high speed and high speed to low speed, respectively; P _C3 and P _C4 are actual input pressure values of the motor 400 to the travel motor switching valve 100 that controls the travel motor to switch from low speed to high speed and high speed to low speed, respectively. In addition, K ₁ and K ₂ are safety factors that allow the driving motor to stabilize at high speed after being switched from low speed to high speed, and safety factors that are stable at low speed after being switched from high speed to low speed, respectively.

With the improvement of the traveling motor switching valve 100, the present invention allows the valve core 1 of the traveling motor switching valve 100 to be switched from low speed to high speed and high speed to low speed at two different preset values. By enabling and preventing the input pressure values of the motor 400 after switching to not satisfy the switching boundary conditions, the present invention can effectively prevent the driving motor from repeatedly switching between high speed and low speed, and high load. Reducing the vibration of the civil machine under the condition, which is beneficial for extending the service life of the traveling motor switching valve 100, the traveling motor and the civil machine, improving driving safety, and improving convenience of use.

In the present invention, preferably, K ₁ <1 and / or K ₂ > 1, so that when stable at a speed after switching from low speed to high speed and / or high speed to low speed, the safety factor of the traveling motor is further It will be higher, and it is more reliably prevented that the traveling motor is repeatedly switched between high speed and low speed, and the vibration of the civil machine is reduced more effectively under high load conditions, which is the driving motor switching valve 100, the driving motor and the civil machine. It is more beneficial to prolong service life, improve driving safety, and improve ease of use.

As the execution of the traveling motor switching valve 100 of the present invention, the traveling motor switching valve 100 may further include a first chamber 1a, a second chamber 1b, and a third chamber 1c, The first chamber (1a) is in communication with the external control oil port (X), the third chamber (1c) is in communication with the feedback oil port (C), the second chamber (1b) is the third The second working oil port (L) and the first working oil port (Y) in communication with the working oil port (Z) and during the process in which the valve core (1) moves from the first working position to the second working position And are alternately communicated with each other, and an effective pressure applied area of the second chamber 1b is smaller than an effective pressure applied area of the third chamber 1c. Based on this, to enable the valve core 1 of the traveling motor switching valve 100 to control the traveling motor to switch from low speed to high speed and high speed to low speed at two different preset values. And, in order to ensure that both of the input pressure values of the motor 400 after switching do not satisfy the switching boundary conditions, in the present invention, only the first chamber 1a, the second chamber 1b, and the third Only the effective pressure working areas of the chamber 1c need to be set, which is a simple structure, low cost and high reliability. This will be further explained in cooperation with the embodiment shown in FIGS. 1-4.

The invention is further described below with reference to FIGS. 1-4.

For ease of understanding, the operating principle of the traveling motor system will first be described with reference to FIG. 1.

1, the traveling motor system includes a floating motor, a traveling motor switching valve 100, a pressure selection valve 300 and a balance valve 200, and the like, and the traveling motor includes a motor 400 Swash plate control mechanism 500, and the like.

The inclined plate control mechanism 500 connected to the inclined plate of the motor 400 is driven to rotate the inclined plate to change the swing angle of the inclined plate. As shown in Fig. 1, the inclined plate control mechanism 500 of this embodiment is specifically a hydraulic cylinder, and the rod of the hydraulic cylinder is connected to the inclined plate. Based on this, when oil is filled in a chamber without a load of the inclined plate control mechanism 500, the inclined plate control mechanism 500 drives the inclined plate to pivot to a position at a smaller angle, thereby driving the motor in a low speed mode. Enable conversion; When oil in the chamber without the load of the swash plate control mechanism 500 flows back to the oil tank, the swash plate control mechanism 500 drives the swash plate to pivot to a larger angle position, so that the traveling motor can be switched to the high speed mode. To make.

The motor 400 is connected to oil ports A and B through the balance valve 200. When one of the oil port (A) and the oil port (B) supplies oil to the motor 400, the oil discharge of the motor 400 is through the other of the oil port (A) and the oil port (B) Outflow, the motor 400 is driven to rotate clockwise or counterclockwise accordingly.

The traveling motor switching valve 100 is for controlling so that the chamber without the rod of the inclined plate control mechanism 500 is alternately switched in communication with one of the oil supply source and the oil tank, whereby the load of the inclined plate control mechanism 500 is By controlling whether oil is supplied to the missing chamber, switching of the driving motor between the high speed mode and the low speed mode can be controlled. As shown in FIG. 1, in this embodiment, the traveling motor switching valve 100 communicates with a chamber without a load of the inclined plate control mechanism 500, and the balance valve (through the pressure selection valve 300) 200). Specifically, the pressure selection valve 300 is a shuttle valve; The first working oil port (Y) of the traveling motor switching valve 100 is in communication with the outlet of the pressure selection valve 300, the two inlets of the pressure selection valve 300 through the balance valve 200 Respectively connected to the oil port (A) and the oil port (B); A second working oil port (L) of the traveling motor switching valve (100) communicates with an oil tank; The third working oil port Z of the traveling motor switching valve 100 is in communication with a rodless chamber of the inclined plate control mechanism 500.

By arranging the pressure selector valve 300, the first working oil port Y is always in communication with the larger of the oil port A and the oil port B. Since the larger pressure value among the oil port (A) and the oil port (B) is the oil supply pressure, while the input pressure or the actual operating pressure of the motor 400, the first working oil port (Y) is always In communication with the oil source, the pressure value P _Y of the first working oil port Y is substantially the same as the actual working pressure value of the motor 400.

As shown in FIG. 1, in order to enable the traveling motor switching valve 100 to control the loadless chamber of the inclined plate control mechanism 500 to be alternately switched with one of the oil supply source and the oil tank, the The travel motor switching valve 100 has a first operating position (the left position in FIG. 1) and a second operating position (the right position in FIG. 1). As shown in Figure 1, in the first operating position, the first working oil port (Y) is blocked and the second working oil port (L) is in communication with the third working oil port (Z). As the chamber without the load of the control mechanism 500 communicates with the oil tank by the traveling motor switching valve 100, the pressure in the chamber without the load of the gradient plate control mechanism 500 is relieved, and the pressure of the gradient plate control mechanism 500 is reduced. The cylinder rod is retracted by the reaction force of the inclined plate, whereby the inclined plate is driven to rotate in the horizontal direction from the vertical direction in FIG. 1, and the swing angle of the inclined plate increases to the maximum value, The output shaft speed of the motor 400 is reduced to a minimum value, and the traveling motor can be operated in a low speed mode; In the second operating position, the first working oil port (Y) is in communication with the third working oil port (Z) and the second working oil port (L) is blocked, in this way, the load of the inclined plate control mechanism 500 Without the chamber is communicated to the oil supply by the traveling motor switching valve 100, the high-pressure oil flows through the traveling motor switching valve 100 into the chamber without the load of the inclined plate control mechanism 500, whereby the inclined plate The cylinder rod of the control mechanism 500 is pushed to be extended to the outside, and the inclined plate is driven to pivot in the vertical direction of FIG. 1, the turning angle of the inclined plate is reduced to a minimum value, and the output shaft speed of the motor 400 is maximum The value increases, and the driving motor can be operated in a high speed mode. The first operating position and the second operating position of the valve core 1 correspond to a low speed mode (a low speed operating state called a first operating state) and a high speed mode (a high speed operating state called a second operating state) of the traveling motor, respectively. do.

In addition, as can be seen in Figure 1, the travel motor switching valve 100 further includes an external control oil port (X) and a feedback oil port (C). The external control oil port (X) is a pilot-controlled oil port for guiding oil to the traveling motor switching valve 100 to control the traveling motor switching valve 100 to switch from the first operating position to the second operating position. Plays a role. The feedback oil port (C), the driving motor switching valve 100 to facilitate switching between the first operating position and the second operating position, the operating pressure of the motor 400 of the traveling motor to the valve It is for feedback to the core 1, thereby controlling the driving motor more accurately to complete the switching according to actual needs. As described above, since the pressures of the first working oil port Y and the feedback oil port C are both the actual working pressure of the motor 400, the pressure P ₁ of the first working oil port Y is ) Is equal to the pressure (P _C ) of the feedback oil port (C).

In the prior art, the driving motor switching valve has only one critical condition for controlling the switching of the driving motor, that is, a condition in which the working pressure of the motor reaches a preset value, that is, the feedback oil port C There is a condition that the pressure P _C becomes equal to the preset value, which means that the traveling motor switching valve in the prior art realizes control of switching from high speed to low speed and from low speed to high speed according to the same preset value. do. The problem is that, since the maximum input power of the traveling motor is a constant value, and the output torque of the traveling motor is proportional to the working pressure and displacement, the pressure of the motor input port will be lower than the preset value after switching from high speed to low speed. , The threshold condition for switching from low speed to high speed is satisfied, and accordingly, the travel motor switching valve will control the travel motor to return to high speed mode automatically, but after return to high speed mode, the motor input port The pressure will rise to a preset value, and then the threshold condition of switching from high speed to low speed is satisfied, so the drive motor switching valve will control the drive motor to automatically switch back to the low speed mode. By repeating this process, the traveling motor cannot be maintained in the desired low speed mode, and is repeatedly switched between high speed and low speed, which causes the civil machine to vibrate under high load conditions, and accordingly the switching valve itself, the traveling motor and the civil machine It not only affects the lifespan and safety of the product, but also reduces the convenience of the product.

In order to solve the problem that the traveling motor is repeatedly switched between high speed and low speed, the structure of the traveling motor switching valve 100 is improved in this embodiment, which will be described in detail with reference to FIGS. 2-4 below. .

2-3, in this embodiment, the travel motor switching valve 100 is disposed within the shell of the motor 400, and the valve core 1, the first plunger ( 21), second plunger 22, first plugging piece 31, second plugging member 32, spring 4, first working oil port (Y), second working oil port ( L), a third working oil port (Z), an external control oil port (X), a first chamber (1a), a second chamber (1b) and a third chamber (1c); Moreover, the traveling motor switching valve 100 does not include a valve body, uses the sheath 5 as a valve body, and the valve core 1 of the traveling motor switching valve 100 is the It is arranged directly inside the sheath 5, while the first working oil port Y, the second working oil port L, the third working oil port Z of the traveling motor switching valve 100, the external control The oil port (X) and the feedback oil port (C) are both arranged on the inner wall of the sheath (5).

By disposing the traveling motor switching valve 100 inside the sheath 5, the traveling motor switching valve 100 and the motor 400 are integrated as a single structure, so that the structure is more compact and the space occupied is reduced. do. By using the sheath 5 as a valve body, there is no need to provide a special valve body separately to accommodate the valve core 1 and oil ports of the traveling motor changeover valve 100, thereby further enhancing its structure. Simplifies, saves cost and facilitates maintenance.

Specifically, as can be seen in FIG. 3, in this embodiment, the second through-hole 51 is attached to the sheath 5 in order to facilitate the placement of the valve core 1 inside the sheath 5. And the valve core 1 is disposed in the second through-hole 51. Since the second through-hole 51 is used to receive the valve core 1, processing is facilitated and disassembly and assembly of the valve core 1 is facilitated. The second through-hole 51 may be disposed on the back cap of the sheath 5 (ie, on the rear cap of the motor).

The valve core 1 realizes switching between the first operating position (the right position in FIG. 2-3) and the second operating position (the left position in FIG. 2-3) of the travel motor switching valve 100. To this end, it can be moved to control the on / off state of the first working oil port (Y), the second working oil port (L), and the third working oil port (Z) of the traveling motor switching valve (100). . 3, in this embodiment, the valve core 1 has a first axial end (ie, the right end in the figure) and a second axial end (ie, the left end in the figure), 4, the first axial end and the second axial end of the valve core 1 have a first plunger chamber 1f and a second plunger chamber 2g, respectively. The effective pressure applied area of the first plunger chamber 1f is smaller than the effective pressure applied area of the second plunger chamber 1g. Here, it is understood that the first plunger chamber 1f and the second plunger chamber 1g are not limited to the two axial end surfaces of the valve core 1, and may each include one section. It is not difficult.

2 and 3, in this embodiment, the first plunger 21 and the second plunger 22 are disposed inside the first plunger chamber 1f and the second plunger chamber 1g, respectively. do. Freely slidable sealing strips are between the inner walls of the first plunger 21 and the first plunger chamber 1f and between the inner walls of the second plunger 22 and the second plunger chamber 1g. Is formed on. During the process of the valve core 1 moving from the first operating position to the second operating position, the first plunger 21 extends relative to the first plunger chamber 1f, and the second plunger 22 is Retract against the second plunger chamber 1g; On the other hand, during the process of the valve core 1 moving from the second operating position to the second operating position. The first plunger 21 retracts with respect to the first plunger chamber 1f, and the second plunger 22 extends with respect to the second plunger chamber 1g.

Based on the above arrangement, as can be seen from FIGS. 2 and 3, the sealing chambers designated as the second chamber 1b and the third chamber 1c are respectively the first plunger 21 and the first plunger chamber ( It is formed between the inner walls of 1f) and between the second plunger 22 and the inner walls of the second plunger chamber 1g. That is, in this embodiment, the second chamber 1b and the third chamber 1c are formed in the valve core 1 and are respectively located at the first axial end and the second axial end of the valve core. . The effective pressure working area of the second chamber 1b is the effective pressure working area of the first plunger chamber 1f, and the effective pressure working area of the third chamber 1c is that of the second plunger chamber 1g. The effective pressure working area, the effective pressure working area of the first plunger chamber 1f is smaller than the effective pressure working area of the second plunger chamber 1g, and accordingly, the effective pressure working area of the second chamber 1b Is smaller than the effective pressure applied area of the third chamber 1c.

Moreover, as shown in Figs. 2 and 3, in this embodiment, the second chamber 1b and the third chamber 1c are configured to communicate with all the oil ports in the following manner, according to the scheme , The third chamber (1c) is in communication with the feedback oil port (C); The second chamber (1B) is in communication with the third working oil port (Z), the second working oil port (L) and during the process of the valve core 1 is moved from the first working position to the second working position and It is in continuous communication with the first working oil port (Y). That is, when the valve core 1 is in the first operating position (as shown in FIG. 2), the second chamber 1b includes a third working oil port Z and a second working oil port ( L), and when the valve core 1 is in the second operating position (as shown in FIG. 3), it is in communication with the third working oil port Z and the first working oil port Y. .

In order to allow the second chamber 1b to easily communicate with the second working oil port L or the first working oil port Y, as shown in FIG. 4, in this embodiment, the first passage ( 1d) is disposed on the valve core 1, and the second chamber 1b communicates with one of the first working oil port Y and the second working oil port L by the first passage 1d. do. 2, in the first operating position, the second chamber 1b communicates with the second working oil port L through the first passage 1d, as shown in FIG. , In the second operating position, the second chamber 1b communicates with the first working oil port Y through the first passage 1b. Similarly, in order to allow the third chamber 1c to easily communicate with the feedback oil port C, in this embodiment, as shown in FIG. 4, the second passage 1e has a valve core 1 The third chamber 1c is in communication with a feedback oil port C by the second passage 1e. Specifically, as can be seen from FIG. 4, both the second chamber 1b and the third chamber 1c extend along the axial direction of the valve core 1, and the first passage 1d and Since both the second passages 1e extend along the radial direction of the valve core 1, the arrangement of two chambers and two passages in the valve core 1 is more reliable and more compact, and machining It becomes more convenient.

Also, as shown in Fig. 4, in this embodiment, a necking section is arranged at the first axial end of the valve core 1. In this way, when it is necessary to disassemble the valve core 1, it becomes convenient for an operator or a separation tool to extend into the second through-hole 51 to exert a force on the valve core 1, The valve core 1 can be more easily taken out from the second through-hole 51, thereby facilitating disassembly of the valve core 1. Moreover, as shown in FIG. 4, a recess 15 is further disposed on the circumferential surface of the neck portion. The concave portion 15 makes it possible to more conveniently apply a force to the neck portion, and the difficulty of disassembling the valve core 1 is further reduced by the concave portion 15.

Further, as shown in FIGS. 2 and 3, in this embodiment, the first stopper member 31 and the second stopper member 32 are respectively provided with a second axial end and a second axial end of the valve core 1. Disposed at one axial end, both the first stopper member 31 and the second stopper member 32 are connected to the sheath 5, respectively, the second axial end side of the valve core 1 And a second axial end side and a first axial end side of the valve core 1 to seal the first axial end side.

2 and 3, the first stopper member 31 is screwed into the second through-hole 51 to seal the second axial end of the valve core 1 It is arranged at the second axial end of the valve core (1). Specifically, screws are formed on the outer circumferential surface of the first stopper member 31 as a whole, and screws are also provided on the inner wall of the corresponding portion of the second through-hole 51, whereby the first by the cooperation of the screws The stopper member 31 may be screwed into the second through-hole 51.

In addition, as shown in FIGS. 2 and 3, a fastening groove 31b is further provided on the surface of the first stopper member 31 away from the valve core 1. The fastening groove 31 is arranged to facilitate disassembly and assembly of the first stopper member 31, which is more important when the first stopper member 31 is screwed inside the sheath 5. Since it is based on the fastening groove 31b, when the first stopper member 31 is disassembled or assembled, a tool can be inserted into the fastening groove 31b, after which the first stopper member 31 is Disassembly and assembly of the first stopper member 31 is achieved by screwing toward the inside of the second through-hole 51 of the sheath 5 or unscrewing toward the outside of the second through-hole 31 This is more convenient and has higher efficiency for disassembly and assembly.

Further, in this embodiment, the first stopper member 31 is configured to support the spring 4. The spring 4 abuts between the first stopper member 31 and the second axial end of the valve core 1 to generate a tendency for the valve core 1 to move from the second operating position to the first operating position. To force it. In particular, in order to facilitate the arrangement of the spring 4, as shown in FIGS. 2 and 3, in this embodiment, a spring on the surface of the first stopper member 31 adjacent to the valve core 1 A receiving chamber 31c is disposed, and the spring 4 is disposed in the spring receiving chamber 31c to abut between the bottom wall of the spring receiving chamber 31c and the second axial end of the valve core 1, In this way, the spring 4 is configured to exert an acting force on the valve core 1 to allow the valve core 1 to move back from the second operating position to the first operating position. Moreover, in the combination of FIGS. 2-4, a spring seat 16 is provided at the second axial end of the valve core 1, so that the spring 4 is connected to the valve core 1 It is fitted to the spring seat (16). A shaft shoulder is provided in an adjacent portion between the valve seat 16 and the valve core 1, and the spring 4 is in contact with the shaft shoulder, so that the spring 4 is a valve The core 1 may be compressed or stretched to change the elastic force exerted on the valve core 1 during the process of moving from the first operating position to the second operating position. Meanwhile, it will be easy to understand that a spring chamber is formed between the spring seat 16, the stopper member 31, and the inner wall of the second through-hole 51.

2 and 3, in this embodiment, a first through-hole 31a is disposed in the first stopper member 31, and the first through-hole 31a accommodates a spring It is in communication with the chamber 31c. Based on this, it is easier to recover the oil as well as decompose. Specifically, the first through-hole 31a extends along the axial direction of the valve core 1, so that the spring receiving chamber 31c communicates with the outside by the first through-hole 31a of a smaller length. Can be. This structure is simpler and oil recovery becomes more convenient.

2 and 3, in this embodiment, the second stopper member 32 is inside the second through-hole 51 to seal the first axial end of the valve core 1 It is screwed and arranged at the first axial end of the valve core (1). Specifically, screws are provided on the entire outer circumferential surface of the second stopper member 32, and screws are also provided on the inner wall of the corresponding portion of the second through-hole 52, so that the second stopper in cooperation with the screws The member 32 may be screwed into the second through-hole 51.

As shown, in this embodiment, the first stopper member 31 and the second stopper member 32 are screwed on both sides in the axial direction of the second through-hole 51. By the method of screw connection, the sealing effect of the said 1st stopper member 31 and the 2nd stopper member 32 becomes favorable.

Also, as shown in FIGS. 2 and 3, in this embodiment, the first chamber 1a is disposed between the first axial end of the valve core 1 and the second stopper member 32. Specifically, the first chamber 1a is between the first axial end of the valve core 1, the second stopper member 32, the first plunger 21 and the inner wall of the second through-hole 51. Located. The first chamber (1a) is in communication with the external control oil port (X), so that the control oil introduced by the external control oil port (X) enters the first chamber (1a) to enter the first of the valve core (1). Acting on the axial end, this creates a tendency for the valve core 1 to move from the first operating position to the second operating position, whereby the valve core 1 is under the control of the external control oil port X. It facilitates switching from the first operating position to the second operating position. To further improve the sealing effect, as shown in FIG. 2, a sealing ring 6 is disposed between the second stopper member 32 and the sheath 5, the sealing ring 6 being the first chamber A tighter seal can be achieved for (1a).

In summary, in an embodiment, the first chamber 1a is located between the first axial end of the valve core 1 and the second stopper member 32 and communicates with an external control oil port X; The second chamber 1b and the third chamber 1c are located in the valve core 1 and are respectively disposed at the first axial end and the second axial end of the valve core 1, and the third chamber 1c ) Is in communication with the feedback oil port (C), the second chamber (1b) is in communication with the third working oil port (Z), the process of moving the valve core (1) from the first operating position to the second operating position The second working oil port (L) and the first working oil port (Y) are in continuous communication.

Specifically, as shown in FIGS. 2-4, the valve core 1 has four sealing sections along the axial direction, the first sealing section 11, the second sealing section 12, and the third sealing, respectively. It includes a section 13 and a fourth sealing section 14, which are sequentially distributed from the first axial end to the second axial end, and the four sealing sections are in contact with the inner wall of the second through-hole 51. Slidably sealed. Between adjacent sealing sections is a necked section. This way, while the valve core 1 is moving from the first operating position to the second operating position, the first chamber 1a, the second chamber 1b, the third chamber 1c and all oil ports are The communication relationship is controlled by the four sealing sections of the valve core 1.

As shown in Fig. 2, when the valve core 1 is in the first operating position (rightmost position in the figure), the second through-between the first chamber 1a and the second working oil port L- The inner wall surface of the hole 51 is sealed by the first sealing section 11, so that the first chamber 1a is isolated from the second working oil port L, whereby the first chamber 1a is only It is guaranteed to communicate with the external control oil port (X); On the other hand, the inner wall surface of the second through-hole 51 between the first chamber 1a and the first working oil port Y is sealed by the second sealing section 12, and the first sealing section 11 The neck portion between and the second sealing section 12 is held away from the inner wall surface of the second through-hole 51 between the second chamber 1b and the second working oil port L, whereby the second The chamber 1b communicates with the second working oil port L and is isolated from the first working oil port Y; The inner wall surface of the second through-hole 51 between the first working oil port Y and the third chamber 1c is sealed by the third sealing section 13, and the third sealing section 13 and 4 The neck portion between the sealing sections 14 is kept away from the inner wall surface of the second through-hole 51 between the third chamber 1c and the feedback oil port C, and the feedback oil port C and spring The inner wall surface of the second through-hole 51 between the chambers is sealed by a fourth sealing section 14 whereby the third chamber 1c is from both the first working oil port Y and the spring chamber. Isolated, but only in communication with the feedback oil port (C).

As shown in Fig. 3, when the valve core 1 is in the second operating position (leftmost position in the figure), the second through-between the first chamber 1a and the second working oil port L- The inner wall surface of the hole 51 is still sealed by the first sealing section 11, whereby the first chamber 1a is isolated from the second working oil port L, and the first chamber 1a is only It is in communication with the external control oil port (X); However, differently, the inner wall surface of the second through-hole 51 between the second chamber 1b and the second working oil port L is sealed by the first sealing section 11, and the first sealing section The neck portion between 11 and the second sealing section 12 is kept away from the inner wall surface of the second through-hole 51 between the second chamber 1b and the first working oil port Y, thereby The second chamber 1b communicates with the first working oil port Y but is changed to be isolated from the second working oil port L; Even if the third sealing section 13 and the fourth sealing section 14 move toward the left, the neck portion between the third sealing section 13 and the fourth sealing section 14 is fed back with the third chamber 1c. The second through-hole 51 is maintained away from the inner wall surface of the second through-hole 51 between the oil ports C, while the second through-hole 51 between the first working oil port Y and the third chamber c The inner wall surface of is still sealed by the third sealing section 13, and the inner wall surface of the second through-hole 51 between the feedback oil port C and the spring chamber is still by the fourth sealing section 14 Sealed, whereby the third chamber 1c is still isolated from the first working oil port Y and the spring chamber, but only in communication with the feedback oil port C.

As can be seen in this embodiment, when the valve core 1 is in the first operating position, the first chamber 1a communicates with the external control oil port X, and the second chamber 1b is 2 is in communication with the working oil port (L) and the third working oil port (Z) but is isolated from the first working oil port (Y), the third chamber (1c) is in communication with the feedback oil port (C); When the valve core 1 is in the second operating position, the first chamber 1a is in communication with the external control oil port X, and the second chamber 1b is the first working oil port Y and the third It is in communication with the working oil port Z but is isolated from the second working oil port L, and the third chamber 1c is in communication with the feedback oil port C.

Hereinafter, principles and boundary conditions for controlling the switching by the traveling motor switching valve 100 in this embodiment will be described with reference to FIGS. 2 and 3.

First, for convenience of explanation, the pressures of the first working oil port (Y), the first working oil port (L), the first working oil port (Z), the external control oil port (X) and the feedback oil port (C) are It is defined as P _Y , P _L , P _Z , P _X and P _C respectively, and the effective pressure operating areas of the first chamber 1a, the first chamber 1b and the third chamber 1c are A ₁ and A ₂ respectively. And A ₃ , the forces exerted on the valve core 1 by the spring 4 in the first and second operating positions are defined as F ₁ and F ₂ , respectively, and the first operating position and the second The displacements of the motor 400 in the operating position are defined as V ₁ and V ₂ respectively. Since the second working oil port L communicates with the oil tank, it can be regarded as P _L = 0. Additionally, as mentioned above, the second working oil port (Y) and the feedback oil port (C) are actually the actual working pressure of the motor 400, thus P _Y = P _C.

Based on the above, as shown in FIG. 2, when the valve core 1 is in the first operating position, the first chamber 1a communicates with the external control oil port X, and the second chamber ( 1b) is in communication with the second working oil port (L) and the third working oil port (Z), the third chamber (1c) is in communication with the feedback oil port (C), the elastic force of the spring is F ₁ . Accordingly, the force balance equation of the valve core 1 at this point, under the condition that the influence of the hydraulic pressure and friction on the sliding of the valve core 1 inside the second through-hole 51 are neglected. Can be obtained as follows.

P _X × A ₁ + P _L × A ₂ = P _C × A ₃ + F ₁ (1)

Since P _L = 0, under the action of the control pressure P _X of the external control oil port X, in order to push the valve core 1 from the first operating position to the second operating position, or in other words, the traveling motor It can be inferred that in order to switch from the low speed mode to the high speed mode, the pressure PC of the feedback oil port C (actual operating pressure of the motor 400) must satisfy the following equation.

P _C <(P _X × A ₁ -F ₁ ) / A ₃ (2)

It can be seen that under the action of the control pressure P _X of the external control oil port X, the boundary condition (referred to as boundary condition 1) for switching the traveling motor from the low speed mode to the high speed mode must satisfy the following equation. have.

P _C1 = (P _X × A ₁ -F ₁ ) / A ₃ (3)

P _C1 is called the first preset value. When the pressure of the feedback oil port C is smaller than the first preset value P _C1 , the valve core 1 moves from the first operating position to the second operating position.

As shown in Fig. 3 and mentioned above, when the valve core 1 is in the second operating position, the first chamber 1a is in communication with the external control oil port X, and the second chamber 1b is The first working oil port Y and the third working oil port Z are in communication, the third chamber 1c is in communication with the feedback oil port C, and the elastic force of the spring 4 is F ₂ . Accordingly, under the condition of ignoring the influence of hydraulic pressure and friction regarding sliding of the valve core 1 inside the second through-hole 51, at this point, the force balance equation of the valve core 1 can be obtained as follows. have.

P _X × A ₁ + P _Y × A ₂ = P _C × A ₃ + F ₂ (4)

Since P _Y = P _C , to allow the valve core to move from the second operating position to the first operating position, that is, to enable the traveling motor to switch from the high speed mode to the low speed mode, the feedback oil port C It can be inferred that the pressure (PC) (actual working pressure of the motor 400) must satisfy the following equation.

P _C > (P _X × A ₁ -F ₂ ) / (A ₃ -A ₂ ) (5)

It can be seen that the boundary condition (referred to as boundary condition 2) for switching the driving motor from the high speed mode to the low speed mode must satisfy the following equation.

P _C2 = (P _X × A ₁ -F ₂ ) / (A ₃ -A ₂ ) (6)

P _C2 is called the second preset value. When the pressure of the feedback oil port C is greater than the second preset value P _C2 , the valve core 1 moves from the second operating position to the first operating position.

In order to prevent repetitive switching caused by switching based on the same preset value, in this embodiment, the first preset value and the second preset value are set so as not to be identical, whereby formula (3) and formula ( Based on 6), a correspondence between the areas of the three chambers A ₁ , A ₂ and A ₃ is obtained.

Moreover, in this embodiment, based on the consideration of displacements of the traveling motor in the high speed mode and the low speed mode, the areas of the three chambers A ₁ , A ₂ and A ₃ , after switching from the low speed mode to the high speed mode, the motor It is configured to control the working pressure value of the motor 400 after switching so that the working pressure value of 400 does not satisfy the boundary condition 2, whereby the motor 400 is stably maintained in the high speed mode as expected, and the high speed After switching from the mode to the low-speed mode, the operating pressure of the motor 400 does not satisfy the boundary condition 1, and accordingly, the motor 400 is stably maintained in the low-speed mode as expected, and switching between high and low speeds is repeated. Prevent the phenomenon more effectively.

For convenience of explanation, after the valve core 1 is moved from the first operating position to the second operating position (i.e., after the traveling motor is switched from low speed to high speed), the oil pressure of the feedback oil port C (i.e. , The operating pressure of the motor 400 is defined as the first operating value P _C3 , and after the valve core 1 moves from the second operating position to the first operating position (that is, the traveling motor is from high speed to low speed) ), The oil pressure of the feedback oil port C (that is, the operating pressure of the motor 400) is defined as the second operating value P _C4 .

Based on this, in order to facilitate control so that the motor stabilizes in the high-speed mode, so that the operating pressure value of the motor 400 does not satisfy the boundary condition 2 after switching from low speed to high speed, in this embodiment, the 1 The operating value (P _C3 ) satisfies the following boundary condition (called boundary condition 3):

P _C3 <K ₁ P _C2 , K ₁ <1 (7)

The maximum input power of the motor 400 is a constant value, and the output torque (T), displacement (V), and input port pressure (P) of the motor 400 (that is, the working pressure) is T = K × V × P. Satisfied, where K is a proportionality constant. Accordingly, the output torque T of the motor 400 is proportional to the displacement V of the motor 400 and the input port pressure P (that is, the actual operating pressure), so that the operating pressure of the motor switched from low speed to high speed In the case of P _C1 , the operating pressures P _C3 and P _C1 after switching satisfy: P _C3 × V ₂ = P _C1 × V ₁ , and the first operating value P _C3 is inferred by the following equation. Can be:

P _C3 = (V ₁ / V ₂ ) P _C1 (8)

Additionally, based on the formulas (7), (8) and (3), the correspondence between the areas of the three chambers (A ₁ , A ₂ and A ₃ ) is determined.

In addition, similarly, in this embodiment, in order to ensure that the actual operating pressure of the motor 400 after switching from high speed to low speed does not satisfy boundary condition 1, and to facilitate control so that the motor is recognized in low speed mode, , The second operating value (P _C4 ) satisfies the following boundary condition (called boundary condition 4):

P _C4 > K ₂ P _C1 , K ₂ > 1 (9)

When the operating pressure of the motor switched from low speed to high speed is PC ₂ , the operating pressures P _C4 and P _C2 after conversion satisfy: P _C4 × V ₁ = P _C2 × V ₂ , and the second operating value (P _C4 ) can be inferred by the following equation:

P _C4 = (V ₂ / V ₁ ) P _C2 (10)

Additionally, based on Eq. (10), Eq. (9) and Eq. (6), the correspondence between the areas of the three chambers A ₁ , A ₂ and A ₃ is determined.

From the above description, the relationship between the effective pressure applied areas A1, A2 and A3 of the first chamber 1a, the second chamber 1b and the third chamber 1c is the boundary condition 1, the boundary condition 2, It can be determined based on boundary condition 3 and boundary condition 4. In other words, by designing the effective pressure acting areas A1, A2 and A3, the travel motor switching valve 100 is configured to remain stable in the desired speed mode after switching, and repeated switching to cause the entire machine to vibrate It is configured not to happen.

Accordingly, according to boundary condition 1, boundary condition 2, boundary condition 3, and boundary condition 4, as shown in FIGS. 2-4, the effective pressure applied area of the first chamber 1a of the traveling motor switching valve 100 ( A1), by designing and confirming the effective pressure applied area A2 of the second chamber 1b and the effective pressure applied area A3 of the third chamber 1c, the traveling motor makes repeated switching between high speed and low speed. Prevent effectively. After the design is completed, the operation process of the traveling motor switching valve 100 may be as follows:

When the actual operating pressure of the traveling motor is greater than P _C1 , the external control oil cannot push the valve core 1 toward the left, and the traveling motor can only operate in the low speed mode; When the actual operating pressure of the traveling motor is less than P _C1 , the external control oil pushes the valve core 1 toward the left, and when the valve core reaches the leftmost position and is switched to the second operating position (the driving motor is in high speed mode. ), Due to the limitation of boundary condition 3, the pressure of the traveling motor will be lower than K ₁ P _C2 , and in this case, since boundary condition 2 is not satisfied, the traveling motor can operate stably in the high speed mode. ; When the actual operating pressure of the traveling motor is greater than P _C2 , the valve core 1 is moved to the right by the interaction of the spring force and all closed chambers, due to the limitation of boundary condition 4, the traveling motor is in low speed mode When switched to, the pressure of the driving motor will be greater than K ₂ P _C1 , in this case boundary condition 1 is not satisfied, and the driving motor can operate stably in the low speed mode.

As shown, in this embodiment, a driving motor switching valve 100 having a first chamber 1a, a second chamber 1b and a third chamber 1c is provided, and the first chamber 1a, By designing the effective pressure areas A ₁ , A ₂ and A _{3 of} the second chamber 1b and the third chamber 1c respectively, the traveling motor will remain stable in the corresponding switched operating mode without frequent switching. By doing so, it is possible to effectively solve the vibration problem of the entire machine, which is beneficial for extending the life of the traveling motor switching valve 100, the traveling motor and even the civil machine, and improving the safety of the civil machine. Moreover, since no additional control elements and detection elements are required, the overall structure is relatively simple, the control is convenient, the control accuracy and operating reliability are relatively high, while the cost is also relatively low.

In other embodiments not shown, the second chamber 1b and the third chamber 1c may not be disposed in the valve core 1, which are between the valve core 1 and the sheath 5 or the valve core It may be disposed between (1) and a specific valve body (valve body), for example, in this embodiment the second chamber (1b) and the third chamber (1c) is arranged in the valve core (1) , As long as the structure of the traveling motor switching valve 100 is relatively simple and compact, the oil path design is relatively convenient, and the structure of the valve core 1 is mainly designed, there is a risk of repeated switching between high speed and low speed. It has the advantage of simple and convenient reduction.

In addition, even if the diameters of the four sealing sections of the valve core 1 shown in FIG. 4 are the same, it will be understood that this does not constitute a limitation to the present invention, for example, different of the valve core 1 is different. The sealing sections may be configured to have different diameters, or it may be possible to place some auxiliary holes in the casing 5.

Based on the travel motor switching valve 100 of the present invention, the present invention provides a travel motor and a civil engineering machine. The traveling motor includes a motor 400 and an inclined plate control mechanism 500 connected to an inclined plate of the motor 400, and further includes a traveling motor switching valve 100 of the present invention. The travel motor switching valve 100 is disposed inside the shell 5 of the motor 400. The civil machine includes the driving motor of the present invention, and may be, for example, a crawler machine such as an excavator.

The above are only exemplary embodiments of the present invention, and are not intended to limit the present invention. Any alterations, equivalent replacements, improvements, etc. made within the spirit and principles of the invention are included within the scope of the invention.

Claims (15)

As a travel motor shift valve (100),
Valve core (1), first working oil port (Y), second working oil port (L), third working oil port (Z), external control port (X) and feedback oil port (C), wherein the valve core 1 has a first operating position and a second operating position; In the first working position, the first working oil port (Y) is blocked and the second working oil port (L) is in communication with the third working oil port (Z); In the second working position, the first working oil port (Y) communicates with the third working oil port (Z) and the second working oil port (L) is blocked;
The first working oil port Y is for communicating with an oil source, the second working oil port L is for communicating with an oil tank, and the third working oil port Z is To communicate with the swashplate control mechanism 500 of the travel motor; The externally controlled oil port (X) guides oil to act on the first axial end of the valve core (1), thereby creating a tendency for the valve core (1) to move from the first operating position to the second operating position. The feedback oil port (C) is fed back to the second axial end of the valve core (1) by the operating pressure of the motor (400) of the traveling motor, the valve core (1) is removed To make it possible to generate a tendency to move from the 2 operating position to the first operating position;
The travel motor switching valve 100 is:
The valve core 1 is configured to move from a first operating position to a second operating position when the oil pressure of the feedback oil port C is less than a first preset value P _C1 , and the The valve core 1 is configured to move from the second operating position to the first operating position when the oil pressure of the feedback oil port C is greater than the second preset value P _C2 , and the first preset value (P _C1 ) is not the same as the second preset value P _C2 ;
After the valve core 1 moves from the first operating position to the second operating position, the oil pressure in the feedback oil port C is a first working value P _C3 , and the valve core 1 ) After switching from the second operating position to the first operating position, the oil pressure in the feedback oil port (C) is the second operating value (P _C4 ), the first operating value (P _C3 ) and the second dictionary The relationship between the set values P _C2 is P _C3 <K ₁ P _C2 , K ₁ ≤1, and the relationship between the second operating value P _C4 and the first preset value P _C1 is P _C4. > K ₂ P _C1 , traveling motor switching valve, configured to be K ₂ ≥1. According to claim 1,
Further comprising a first chamber (1a), a second chamber (1b) and a third chamber (1c), the first chamber (1a) is in communication with the external control oil port (X), the third chamber ( 1c) is in communication with the feedback oil port (C), the second chamber (1b) is in communication with the third working oil port (Z) and the valve core (1) is in a second operating position from the first operating position During the process of moving to the second working oil port (L) and the first working oil port (Y) is configured to be alternately switched, and the effective working area of the second chamber (1b) is the third chamber The travel motor switching valve smaller than the effective pressure working area of (1c). According to claim 2,
Further comprising a spring (4), the spring (4) is disposed at a second axial end of the valve core (1) so that the valve core (1) is removed from the second operating position in the valve core (1). 1 acting force is applied to generate a tendency to move to the operating position, and the first preset value P _C1 is P _C1 = (P _X × A ₁ -F ₁ ) / A ₃ , The second preset value P _C2 is P _C2 = (P _X × A ₁ -F ₂ ) / (A ₃ -A ₂ ), and the first operating value P _C3 is P _C3 = (V ₁ / V ₂ ) P _C1 , the second operating value P _C4 is P _C4 = (V ₂ / V ₁ ) P _C2 , where P _X is the oil pressure of the external control oil port (X), A ₁ , A ₂ and A ₃ are effective pressure applied areas of the first chamber 1a, the second chamber 1b and the third chamber 1c, respectively, F ₁ and F ₂ are respectively the first operating position And the acting forces of the spring 4 applied to the valve core 1 in the second operating position, and V ₁ and V ₂ are displacements of the motor 400 in the first operating position and the second operating position, respectively. Travel motor switching valve. According to claim 2,
The second chamber (1b) and the third chamber (1c) is disposed on the valve core (1), respectively, the first axial end and the second axial end of the valve core (1), the traveling motor Switching valve. The method of claim 4,
A first plunger chamber 1f and a second plunger chamber 1g are provided at the first axial end and the second axial end of the valve core 1, respectively; A first plunger 21 is disposed inside the first plunger chamber 1f, and a second plunger 22 is disposed inside the second plunger chamber 1g; The second chamber 1b is located between the first plunger 21 and the inner wall of the first plunger chamber 1f, and the third chamber 1c has the second plunger 22 and the second plunger. The travel motor switching valve located between the inner walls of the chamber 1g. The method of claim 4,
A first passage 1d is disposed in the valve core 1, and the second chamber 1b is provided with the first working oil port Y and the second working oil port through the first passage 1d. (L); And / or a second passage 1e is disposed in the valve core 1, and the third chamber 1c communicates with the feedback oil port C through the second passage 1e. Switching valve. According to claim 1,
Further comprising a first plugging piece 31 disposed at a second axial end of the valve core 1; The spring 4 of the travel motor switching valve 100 is in contact between the first stopper member 31 and the second axial end of the valve core 1 and the valve core 1 is connected to the valve core 1. ) A traveling motor changeover valve, configured to exert an acting force to cause a tendency to move from the second operating position to the first operating position. The method of claim 7,
A spring receiving chamber (31c) is provided on the surface of the first stopper member (31) adjacent to the valve core (1), and the spring (4) is disposed inside the spring receiving chamber (31c), switching a traveling motor valve. The method of claim 8,
The first through-hole 31a is disposed in the first stopper member 31, and the first through-hole 31a is in communication with the spring receiving chamber 31c. The method of claim 7,
A traveling motor switching valve, wherein a fastening groove (31b) is disposed on the surface of the first stopper member (31) away from the valve core (1). According to claim 1,
A travel motor switching valve, wherein a necking section is disposed at the first axial end of the valve core (1). The method of claim 11,
A travel motor switching valve, wherein a recess (15) is disposed on the circumferential surface of the abdomen. As a travel motor,
It includes a motor 400 and a swashplate control mechanism 500 connected to the inclined plate of the motor 400, and further includes a traveling motor switching valve 100 according to claim 1, wherein the traveling motor The switching valve 100 is disposed inside the shell 5 of the motor 400, a traveling motor. The method of claim 13,
A second through-hole 51 is disposed in the sheath 5, and a valve core 1 of the traveling motor switching valve 100 is disposed inside the second through-hole 51, and the traveling motor The first working oil port (Y), the second working oil port (L), the third working oil port (Z), the external control port (X), and the feedback oil port (C) of the changeover valve 100 are all of the above shell. The driving motor, which is arranged on the inner wall of (5). An engineering machinery comprising a driving motor according to claim 13.

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