CN215568123U

CN215568123U - Electromagnetic change valve

Info

Publication number: CN215568123U
Application number: CN202121404887.2U
Authority: CN
Inventors: 黄路路; 李瑞锋
Original assignee: Bosch Rexroth Changzhou Co Ltd
Current assignee: Bosch Rexroth Changzhou Co Ltd
Priority date: 2021-06-23
Filing date: 2021-06-23
Publication date: 2022-01-18
Anticipated expiration: 2031-06-23

Abstract

A solenoid directional valve comprising: a valve body (1) defining a valve chamber (11); a valve body (2) mounted in the valve chamber (11) in an axially slidable manner; an electromagnet (3) that acts on the valve element (2) in a first axial direction when energized; and a return spring (5) acting on the spool (2) in an axial second direction; the maximum working pressure of the electromagnetic directional valve is 350bar, and the maximum spring force range of the return spring (5) under the maximum compression amount when the electromagnet (3) is electrified is 61.4N to 75.1N. The area of the maximum power limit of the solenoid valve is increased.

Description

Electromagnetic change valve

Technical Field

The present application relates to a solenoid directional valve.

Background

Reversing valves are often used in hydraulic systems to control the direction of fluid flow. The reversing valve generally includes a valve body, a valve core, an electromagnet, a return spring, and the like. The spool is normally held in place by an axial spring force applied to its axial end by a return spring. After the electromagnet is electrified, the electromagnet generates actuating force acting on the valve core, and overcomes the spring force of the return spring to move the valve core, so that the reversing valve is switched to an actuating position. After the electromagnet is de-energized, the actuating power of the electromagnet disappears, and the reset spring drives the valve plug to return to the original position valve position.

Generally, under the same conditions, the actuating force of the electromagnet is in positive correlation with the size of the electromagnet, and the larger the size of the electromagnet is, the larger the actuating force is. On the other hand, the spring force is determined by the parameters of the return spring. The greater the spring force, the easier the spool is driven into position by the return spring. However, there are constraints on the size of the solenoid and return spring in view of the overall size of the reversing valve. In addition, the spring force and the actuation force of the electromagnet are too large, which disadvantageously causes a large commutation shock.

It is desirable to optimize the specifications of the electromagnet and the return spring while ensuring that the predetermined performance of the reversing valve is achieved.

SUMMERY OF THE UTILITY MODEL

It is an object of the present application to provide an improved electromagnetic directional valve that is capable of setting the specification parameters of the electromagnet and the return spring within an optimum range while ensuring that a predetermined performance of the directional valve is achieved.

To this end, the present application provides, in one aspect thereof, an electromagnetic directional valve including: a valve body defining a valve chamber; a spool mounted in the valve chamber in an axially slidable manner; an electromagnet which acts on the valve core along a first axial direction when electrified; the return spring acts on the valve core along the axial second direction; the maximum working pressure of the electromagnetic directional valve is 350bar, and the maximum spring force range of the return spring under the maximum compression amount when the electromagnet is electrified is 61.4N-75.1N.

Optionally, the electromagnet has a coil diameter in the range of 38-46 mm.

Optionally, a coil diameter value of the electromagnet and a maximum spring force value of the return spring are in a positive correlation.

Optionally, the diameter of the spool is D; the maximum displacement of the valve core which can move along the first direction when the electromagnet is electrified is S; the reset spring is a cylindrical compression spring, and the outer diameter is d, so that the requirements are met: d is more than or equal to 11.2mm and less than or equal to 13.4 mm; s is more than or equal to 3.8mm and less than or equal to 4.6 mm; and d is more than or equal to 7.5mm and less than or equal to 8.4 mm.

Optionally, the electromagnetic directional valve satisfies: S/D is more than or equal to 0.2 and less than or equal to 0.25; and D/D is more than or equal to 0.58 and less than or equal to 0.72.

Optionally, when the electromagnet loses power, the pretightening force of the return spring is F, and the elastic coefficient of the return spring is K, so that the following requirements are met: k is more than or equal to 17.5N/mm and less than or equal to 21N/mm; and F is more than or equal to 13.5N and less than or equal to 16.5N.

Optionally, the electromagnet is a dc electromagnet.

Optionally, the maximum allowable flow rate of the electromagnetic directional valve is 90 l/min.

Optionally, the electromagnetic directional valve is a two-position four-way directional valve.

Optionally, the electromagnetic directional valve has a home position when the electromagnet is electrified and an actuating valve position when the electromagnet is electrified; in the original position, a port P of the electromagnetic directional valve is communicated with a port A, a port B of the electromagnetic directional valve is communicated with a port T, and in the actuating valve position, the port P is communicated with the port B, and the port A of the electromagnetic directional valve is communicated with the port T; or in the original position, the port P of the electromagnetic directional valve is communicated with the port B, the port A is communicated with the port T, and in the actuating valve position, the port P is communicated with the port A, and the port B is communicated with the port T.

The electromagnetic reversing valve has the advantages that on the premise that the highest working pressure of the reversing valve is met, the optimized maximum spring force range of the reset spring is given, the area of the maximum power limit of the electromagnetic valve is increased, and the reversing valve has higher working performance.

Drawings

The foregoing and other aspects of the present application will be more fully understood and appreciated by reference to the following detailed description, taken with reference to the accompanying drawings, in which:

FIG. 1 is a hydraulic schematic of a solenoid directional valve according to the present application;

FIG. 2 is a cross-sectional view of an exemplary construction of the reversing valve of FIG. 1;

FIG. 3 is a cross-sectional view of the valve body of the reversing valve of FIG. 2;

FIG. 4 is a cross-sectional view of the valve spool of the reversing valve of FIG. 2;

FIG. 5 is a cross-sectional view of the actuation valve position of the reversing valve of FIG. 2;

FIG. 6 is a hydraulic signature of another solenoid directional valve according to the present application;

fig. 7 is a graph of the operating performance of a prior art solenoid operated directional valve.

Figure 8 is a graph of the operating performance of the reversing valve shown in figure 2.

Detailed Description

The present application relates generally to a two-position, four-way electromagnetic directional valve, the hydraulic symbols of which are shown in fig. 1, with four oil ports: a T port (an oil return port), an A port (a working oil port), a P port (an oil inlet) and a B port (a working oil port). The diverter valve has two operating valve positions, the home position shown in FIG. 1, in which the electromagnet is not energized, in which port P is in communication with port A, port B is in communication with port T, and the operating valve position after the electromagnet is energized, in which port P is in communication with port B, and port A is in communication with port T.

Fig. 2 illustrates an exemplary structure in which the electromagnetic directional valve of fig. 1 may be implemented, and details of the structure of the directional valve are shown in fig. 3 and 4. Referring to fig. 1-3, the reversing valve includes: a valve body 1; a valve spool 2 disposed in the valve body 1; an electromagnet 3 mounted at a first end of the valve body 1 and having a push rod 4, the push rod 4 pushing the valve element 2 in a first axial direction (i.e. from left to right in the figure) when the electromagnet 3 is energized; a return spring 5, which in this case is a helical compression spring, is arranged in a plug 6 mounted at the second end of the valve body 1 and urges the valve spool 2 in an axial second direction (i.e. from right to left in the figure), which is opposite to the first direction.

Referring to fig. 3, a valve chamber 11 extending axially is formed in the valve body 1, and a first end of the valve chamber 11 is communicated with the electromagnet installation chamber 12 and a second end is communicated with the blocking installation chamber 13. The spool 2 is axially slidably disposed in the valve chamber 11 to effect switching of the valve positions. A part of the electromagnet 3 is installed in the electromagnet installation cavity 12, and a part of the plug 6 is installed in the plug installation cavity 13.

Oil grooves (undercut grooves) 14, 15, 16, 17, 18 are formed in the valve body 1 in this order in the first direction facing the valve chamber 11, the

oil grooves

14 and 18 communicating through an internal passage 19 in the valve body 1 and both connected to the T-port. Oil groove 15 is connected to port a, oil groove 16 is connected to port P, and oil groove 17 is connected to port B.

Referring to fig. 4, the body of the valve cartridge 2 is cylindrical, and a first end (left end in fig. 4) of the body is a push rod action end, and a second end (right end in fig. 4) of the body is a spring action end, and the second end is formed with a tapered boss 21 for positioning an end of the return spring 5.

Oil grooves (undercut grooves) 22, 23, 24, 25, 26 are formed in this order along the first direction in the body of the valve body 2, leaving uncut spaced

portions

27, 28, 29, 30 between the oil grooves. The axial length and location of these oil grooves are such that they cooperate with the oil grooves in the valve body 1 to effect the aforementioned port communication relationship in both valve positions of the reversing valve.

Specifically, referring to fig. 2 in conjunction with fig. 3 and 4, in the home position of the reversing valve, the electromagnet 3 is not energized, and at this time, the

oil grooves

15 and 16 are communicated with each other via the

oil grooves

23 and 24, the

oil grooves

17 and 18 are communicated with each other via the

oil grooves

25 and 26, the

oil grooves

14 and 15 are separated from each other by the separation portion 27, and the

oil grooves

16 and 17 are separated from each other by the separation portion 29. Therefore, the communication relation among the oil ports under the original position is realized.

When the electromagnet 3 is energized, the electromagnetic force generated by the electromagnet 3 causes the push rod 4 to push the valve core 2 in the first direction (against the spring force of the return spring 5), thereby reaching the actuation valve position shown in fig. 5. At this time,

oil grooves

14 and 15 communicate with each other via

oil grooves

22 and 23,

oil grooves

16 and 17 communicate with each other via

oil grooves

24 and 25,

oil grooves

15 and 16 are separated from each other by a separation portion 28, and

oil grooves

17 and 18 are separated from each other by a separation portion 30. Therefore, the communication relation between the oil ports under the actuating valve position is realized.

It will be appreciated that another solenoid operated directional valve can be implemented by replacing the solenoid 3 to the second end of the valve body 1 and the return spring 5 to the first end of the valve body 1, the hydraulic symbols of which are shown in fig. 6.

When the reversing valve is in the original position, the axial acting force applied to the valve core 2 is as follows: the spring force in the second direction (provided by the pre-compression of the return spring 5).

When the reversing valve is in the actuating valve position, the axial acting force applied to the valve core 2 is as follows: electromagnetic actuation in a first direction (provided by electromagnet 3) and spring force in a second direction (provided by the maximum compression of return spring 5).

When the reversing valve is reversed from the original position to the actuating valve position, the axial acting force applied to the valve core 2 comprises the following components: electromagnetic actuation force in the first direction (provided by electromagnet 3), spring force in the second direction (provided by return spring 5) and hydraulic resistance (generated by the working fluid flowing through the reversing valve), wherein the electromagnetic actuation force is greater than the sum of the spring force and the hydraulic resistance.

When the reversing valve is reversed from the position of the actuating valve to the original position, the axial acting force applied to the valve core 2 comprises the following components: a spring force in the second direction (provided by the return spring 5) and a hydraulic resistance in the first direction (generated by the working fluid flowing through the reversing valve), wherein the spring force is greater than the hydraulic resistance.

The electromagnetic actuation force depends on the size of the electromagnet 3.

The spring force depends on the parameters of the return spring 5 (spring constant, amount of compression).

The hydraulic resistance depends on the opening of the directional valve, the pressure and the flow rate of the working fluid flowing through the directional valve.

The faster the reversing action of the valve core is, the higher the action reliability of the electromagnetic valve is. Therefore, in order to quickly switch the direction of the direction valve from the home position to the operating position, the electromagnetic actuating force, that is, the size of the electromagnet 3 needs to be increased. In order to make the reversing valve quickly reverse from the actuating valve position to the home position, the spring force needs to be increased, which is characterized by the maximum spring force of the return spring 5 at the maximum compression.

As mentioned above, when the electromagnet 3 is energized, the valve core 2 will move in the first direction to compress the return spring 5 until the valve core moves to the mechanical limit position and stops. Referring to fig. 2, it is assumed that the maximum displacement of the spool 2 movable in the first direction is S. The return spring 5 is assumed to be a cylindrical compression spring having an outer diameter d (measurable in the spring's natural state). The diameter of the valve core 2 is D.

When the electromagnet 3 loses power, the return spring 5 is pre-compressed, and the pre-tightening force of the return spring 5 is F. The return spring 5 has a spring constant of K (N/mm).

Then, by taking the maximum power limit area of the electromagnetic directional valve as an optimization target and the structural parameters of the electromagnetic directional valve as optimization variables, the following are determined and selected according to the structural parameter range of the electromagnetic directional valve of the present application through optimization calculation:

11.2≤D≤13.4；

3.8≤S≤4.6；

7.5≤d≤8.4。

further, the structural parameters satisfy:

0.2≤S/D≤0.25；

0.58≤d/D≤0.72。

further, the structural parameters satisfy:

61.4≤F+S*K≤75.1；

17.5≤K≤21；

13.5≤F≤16.5。

where the length (including displacement, diameter, etc.) is in mm and the force is in N.

The above structural parameters are applicable to two types of electromagnetic directional valves represented by symbols in fig. 1 and 6.

For a solenoid operated directional valve, there are typically maximum power limits, i.e., maximum operating pressure (supply pressure) and maximum allowable flow. For example, FIG. 7 illustrates the commutation limits of a prior art solenoid directional valve. The abscissa of the graph is the flow rate and the ordinate is the operating pressure, and curve S1 represents the maximum power limit. It can be seen that the maximum allowable flow is less than 70l/min at a maximum working pressure of 350 bar.

On the premise of ensuring that the maximum working pressure of the reversing valve is 350bar, the maximum spring force of the return spring 5 under the maximum compression amount is determined to be 61.4N to 75.1N by considering the reversing speed of the reversing valve from the position of the actuating valve to the original position, and the method is improved compared with the prior art.

Next, the coil diameter of the electromagnet 3 is matched on the basis of the above-described maximum spring force range in consideration of the reversing speed at which the reversing valve reverses from the home position to the operating valve position, and it is determined that the coil diameter of the electromagnet 3 ranges from 38mm to 46 mm. When the value is taken specifically, the coil diameter of the electromagnet 3 and the maximum spring force of the return spring 5 are in a positive correlation, that is, the coil diameter of the smaller electromagnet 3 corresponds to the smaller maximum spring force of the return spring 5, and the coil diameter of the larger electromagnet 3 corresponds to the larger maximum spring force of the return spring 5.

The electromagnet 3 is a direct current electromagnet with the same type of coil diameter sold in the market.

The maximum power limit that can be achieved with the solenoid directional valve of fig. 2 of the present application using the two ranges described above is represented by curve S2 in fig. 8. It can be seen that the maximum permissible flow rate increases to 90l/min at a constant maximum working pressure of 350 bar. In contrast to the prior art shown in fig. 7, the maximum power limit area (i.e., the area covered by the maximum power limit curve) of the solenoid directional valve of the present application is increased by about 15%.

Therefore, the present application enables the solenoid directional valve to have higher operation performance by matching the range of the coil diameter of the electromagnet 3 with the maximum spring force range of the return spring 5.

Although the present application has been described herein with reference to specific exemplary embodiments, the scope of the present application is not intended to be limited to the details shown. Various modifications may be made to these details without departing from the underlying principles of the application.

Claims

1. A solenoid directional valve comprising:

a valve body (1) defining a valve chamber (11);

a valve body (2) mounted in the valve chamber (11) in an axially slidable manner;

an electromagnet (3) that acts on the valve element (2) in a first axial direction when energized; and

a return spring (5) acting on the spool (2) in the axial second direction;

the electromagnetic directional valve is characterized in that the maximum working pressure of the electromagnetic directional valve is 350bar, and the maximum spring force range of the return spring (5) under the maximum compression when the electromagnet (3) is electrified is 61.4N to 75.1N.

2. A solenoid directional valve according to claim 1, characterized in that the coil diameter of the electromagnet (3) is in the range 38-46 mm.

3. The electromagnetic directional valve according to claim 2, characterized in that the coil diameter of the electromagnet (3) is positively correlated with the maximum spring force of the return spring (5).

4. A solenoid directional valve according to claim 1, characterized in that the diameter of the spool (2) is D; the maximum displacement of the valve core (2) which can move along the first direction when the electromagnet (3) is electrified is S; reset spring (5) are the cylinder type compression spring, and the external diameter is d, then satisfies:

11.2mm≤D≤13.4mm；

s is more than or equal to 3.8mm and less than or equal to 4.6 mm; and is

7.5mm≤d≤8.4mm。

5. The electromagnetic directional valve according to claim 4, characterized by satisfying:

S/D is more than or equal to 0.2 and less than or equal to 0.25; and is

0.58≤d/D≤0.72。

6. The electromagnetic directional valve according to claim 5, characterized in that when the electromagnet (3) loses power, the pretightening force of the return spring (5) is F, and the elastic coefficient of the return spring (5) is K, then the following conditions are satisfied:

k is more than or equal to 17.5N/mm and less than or equal to 21N/mm; and is

13.5N≤F≤16.5N。

7. A solenoid directional valve according to claim 1, characterized in that said electromagnet (3) is a dc electromagnet.

8. The electromagnetic directional valve as set forth in claim 1, characterized in that the maximum allowable flow rate of the electromagnetic directional valve is 90 l/min.

9. The electromagnetic directional valve according to any of claims 1 to 8, characterized in that the electromagnetic directional valve is a two-position four-way directional valve.

10. The electromagnetic directional valve according to claim 9, characterized in that the electromagnetic directional valve has a home position when the electromagnet (3) is energized and an actuation valve position when the electromagnet (3) is energized;

in the original position, a port P of the electromagnetic directional valve is communicated with a port A, a port B of the electromagnetic directional valve is communicated with a port T, and in the actuating valve position, the port P is communicated with the port B, and the port A of the electromagnetic directional valve is communicated with the port T; or

In the original position, the port P of the electromagnetic directional valve is communicated with the port B, the port A is communicated with the port T, and in the actuating valve position, the port P is communicated with the port A, and the port B is communicated with the port T.