JP4631722B2 - solenoid valve - Google Patents

Description

  The present invention relates to an electromagnetic valve that obtains a driving force by an electromagnetic actuator and controls a fluid flow by displacing a spool by the driving force.

[Conventional technology]
Conventionally, electromagnetic valves have been used for switching hydraulic circuits in automatic transmissions, supplying hydraulic pressure in variable valve timing devices, and the like.

  The solenoid valve includes a spool that is displaced from one side in the axial direction by a driving force transmitted from the electromagnetic actuator, and a sleeve that slidably accommodates the spool in the axial direction, and controls the flow of fluid such as hydraulic oil. Further, the internal space on one side of the sleeve is sealed by a spool, and forms a damper chamber into which hydraulic oil flows in and out as the spool is displaced (see, for example, Patent Document 1). The hydraulic oil flows in and out of the damper chamber through a throttle that penetrates the sleeve.

[Problems with conventional technology]
By the way, this diaphragm is a tuning factor that determines the response and stability to the displacement of the spool. That is, the responsiveness and stability of the spool are determined by the position of the diaphragm, the diameter of the diaphragm, and the like. If priority is given to improving the responsiveness and the stability is lowered, when the oil pressure is high, the pulsation of the oil pressure increases and there is a risk that oil vibration will occur. On the other hand, if priority is given to improving the stability and the responsiveness is lowered, when the hydraulic pressure is low, the responsiveness is significantly lowered and the response delay becomes large. Furthermore, since the fluidity of the hydraulic fluid is reduced at extremely low temperatures, the responsiveness is significantly reduced.
JP 2000-220762 A

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to achieve both responsiveness and stability with respect to displacement of a spool in a solenoid valve regardless of the level of fluid pressure.

[Means of Claim 1]
The electromagnetic valve according to claim 1 operates by obtaining a driving force by an electromagnetic actuator and controls the flow of fluid. The driving force is transmitted from the electromagnetic actuator and is displaced to one side in the axial direction. And a sleeve for slidably accommodating the spool in the axial direction. Further, the internal space on one side of the sleeve is sealed by a spool, and forms a damper chamber into which fluid flows in and out as the spool is displaced. The fluid flows in and out of the damper chamber through a restrictor penetrating the sleeve, and the restrictor can change the effective flow path area for the fluid inflow and inflow through the restrictor according to the amount of displacement of the spool. Is provided.

  According to this means, the effective flow path area is varied according to the amount of displacement of the spool, and further, the displacement amount of the spool is varied according to the fluid pressure, so that the effective flow area is varied according to the fluid pressure. . That is, the restrictor is provided so that the flow rate of the fluid passing through the restrictor (the restrictor passing flow rate) can be varied according to the fluid pressure. For example, the throttle is provided so that the flow rate through the throttle decreases as the fluid pressure increases.

  Here, the responsiveness to the displacement of the spool (spool responsiveness) improves as the throttle passage flow rate increases, and decreases as the throttle passage flow rate decreases. On the other hand, the stability against spool displacement (spool stability) improves as the throttle passage flow rate decreases, and decreases as the throttle passage flow rate increases.

  On the other hand, if the throttle is provided as described above, the higher the fluid pressure, the smaller the throttle passage flow rate and the spool stability improves. Conversely, the lower the fluid pressure, the larger the throttle passage flow rate, and the spool. Responsiveness is improved. That is, when the fluid pressure is high, the throttle passage flow rate is reduced to compensate for the decrease in spool stability. Conversely, when the fluid pressure is low, the throttle passage flow rate is increased to compensate for a decrease in spool response. As a result, it is possible to achieve both spool response and spool stability regardless of the fluid pressure level.

[Means of claim 2]
According to the electromagnetic valve of the second aspect, the correlation between the effective flow path area and the amount of displacement of the spool is varied by processing at least one of the peripheral edge of the inner opening of the throttle and the outer periphery of the spool.
Thereby, the correlation between the effective flow path area and the amount of displacement of the spool can be easily changed.

[Means of claim 3]
According to the electromagnetic valve of the third aspect, the fluid is hydraulic oil for obtaining hydraulic pressure, and the displacement amount of the spool is varied according to the hydraulic pressure.
This means shows one application example of the electromagnetic valve.

The electromagnetic valve of the best mode 1 operates by obtaining a driving force by an electromagnetic actuator, and controls the flow of fluid. The driving force is transmitted from the electromagnetic actuator and is displaced to one side in the axial direction. A spool that varies the amount of displacement in response to the spool and a sleeve that slidably accommodates the spool in the axial direction are provided. Further, the internal space on one side of the sleeve is sealed by a spool, and forms a damper chamber into which fluid flows in and out as the spool is displaced. The fluid flows in and out of the damper chamber through a restrictor penetrating the sleeve, and the restrictor can change the effective flow path area for the fluid inflow and inflow through the restrictor according to the amount of displacement of the spool. Is provided.
Further, according to this solenoid valve, the fluid is hydraulic oil for obtaining hydraulic pressure, and the displacement amount of the spool is varied according to the hydraulic pressure.

[Configuration of Example 1]
The structure of the solenoid valve 1 of Example 1 is demonstrated using FIG. 1 thru | or FIG.
The solenoid valve 1 is operated by obtaining a driving force by an electromagnetic actuator (not shown) and controls the flow of fluid. For example, switching of a hydraulic circuit in an automatic transmission or a hydraulic pressure in a valve variable timing device is performed. Used for supply. That is, the solenoid valve 1 controls the flow of hydraulic oil for obtaining hydraulic pressure.

  The solenoid valve 1 includes a spool 2 that is displaced in the axial direction to control the flow of hydraulic oil, a sleeve 3 that slidably accommodates the spool 2 in the axial direction, and a restoration that biases the spool 2 toward the other side in the axial direction. A spring 4.

  The spool 2 includes large-diameter portions 6, 7, and 8 that are in sliding contact with the inner peripheral surface of the sleeve 3 in order from one side in the axial direction. Further, when a driving force is generated in the electromagnetic actuator, the spool 2 is urged to one side in the axial direction by the driving force. Then, the spool 2 is displaced to a position where the driving force and the urging force by the restoring spring 4 are balanced.

The sleeve 3 has various ports such as an import 10, an out port 11, a feedback port 12, and a drain port 13.
The import 10 communicates with the external flow path on the inflow side of the hydraulic oil and forms an inlet for the hydraulic oil into the sleeve 3 and is opened and closed by the large diameter portion 7. Here, the large diameter portion 7 forms an internal flow chamber 15 in which hydraulic oil flows in the sleeve 3 together with the large diameter portion 8, and is displaced in the axial direction to adjust the degree of communication between the internal flow chamber 15 and the import 10. To do.

The out port 11 communicates with the external flow path on the outflow side of the hydraulic oil to form an outlet for the hydraulic oil from the sleeve 3, and is always open to the internal flow chamber 15.
As a result, the hydraulic oil in the inflow side external flow path flows into the internal flow chamber 15 via the flow path whose degree of communication is adjusted, whereby the hydraulic pressure is controlled to a predetermined target value. Then, hydraulically controlled hydraulic oil is supplied from the internal flow chamber 15 to the outflow side external flow path.

  The higher the target value of hydraulic pressure, the greater the degree of communication between the internal fluid chamber 15 and the import 10. Therefore, the higher the target value of the hydraulic pressure, the stronger the driving force generated by the electromagnetic actuator, and the greater the displacement amount of the spool 2 toward the one side in the axial direction. That is, the displacement amount of the spool 2 is varied according to the hydraulic pressure.

  The feedback port 12 forms an inlet for supplying a part of the hydraulic oil supplied to the outflow side external flow path to the feedback chamber 16. Here, the feedback chamber 16 is formed by the large-diameter portion 6 and the large-diameter portion 7, and is a space through which hydraulically controlled hydraulic oil is guided in order to correct the displacement amount of the spool 2. The hydraulic oil in the feedback chamber 16 exerts an urging force by hydraulic pressure on the other side in the axial direction with respect to the large diameter portion 7 based on the difference in cross-sectional area perpendicular to the axial direction between the large diameter portion 6 and the large diameter portion 7. The displacement amount of the spool 2 is corrected.

  The drain port 13 serves as an outlet for discharging the hydraulic oil in the internal flow chamber 15. The drain port 13 is opened by the large-diameter portion 8 when the import 10 is closed and the supply of hydraulic pressure from the inflow side external flow path to the internal flow chamber 15 is stopped. That is, when the generation of the driving force is stopped in the electromagnetic actuator, the large-diameter portion 7 is displaced in the other axial direction to close the import 10, and the large-diameter portion 8 is displaced in the other axial direction to 13 is released. Thereby, the hydraulic fluid in the internal fluid chamber 15 is discharged through the drain port 13.

[Features of Example 1]
According to the solenoid valve 1 of the first embodiment, the internal space on one side of the sleeve 3 is sealed by the large diameter portion 6 and forms a damper chamber 18 into which hydraulic oil flows in and out as the spool 2 is displaced. The hydraulic oil flows in and out of the damper chamber 18 through a throttle 19 that penetrates the sleeve 3. Here, the restrictor 19 is provided so that the effective flow passage area (hereinafter simply referred to as the effective flow passage area) of the hydraulic oil flowing in and out through the restrictor 19 can be substantially varied according to the displacement amount of the spool 2. It has been.

  That is, the inner peripheral surface in the vicinity of the diaphragm 19 and the inner opening 21 is set so that the distance between the inner opening 21 of the diaphragm 19 and the outer peripheral surface of the large diameter portion 6 is sufficiently smaller than the diameter of the inner opening 21. Process. As a result, the large diameter portion 6 opens and closes the diaphragm 19 in accordance with the amount of displacement of the spool 2 to vary the opening area of the diaphragm 19. As a result, the effective flow path area substantially matches the opening area of the diaphragm 19. That is, the effective flow path area is substantially variable according to the displacement amount of the spool 2.

  Here, since the displacement amount of the spool 2 increases as the target value of hydraulic pressure increases, the amount of closure by the large-diameter portion 6 with respect to the internal opening 21 increases as the hydraulic pressure increases, and the effective flow path area decreases. That is, the higher the hydraulic pressure, the smaller the effective flow path area, and the smaller the flow rate of hydraulic oil that passes through the throttle 19 (throttle passage flow rate).

  In the present embodiment, as shown in FIG. 1, the diaphragm 19 is provided at a position where the internal opening 21 is partially closed even when the electromagnetic actuator does not generate a driving force. However, it is not limited to such a form. For example, when the installation position of the throttle 19 is shifted to one side in the axial direction and the large diameter portion 7 opens the import 10 to the internal flow chamber 15, the large diameter portion 6 starts to close the throttle internal opening 21. It may be. Further, the installation position of the throttle 19 is further shifted to the one side in the axial direction, and the large diameter portion 6 closes the internal opening 21 after the large diameter portion 7 opens the import 10 to the internal flow chamber 15. You may make it start.

  Furthermore, the position where the diaphragm 19 is provided may be determined in consideration of the opening area of the diaphragm 19 when the driving force generated by the electromagnetic actuator is maximum (see FIG. 3). Further, the correlation between the effective flow path area and the displacement amount of the spool 2 can be variously changed by processing at least one of the peripheral edge of the internal opening 21 and the outer periphery of the large diameter portion 6.

[Effect of Example 1]
According to the solenoid valve 1 of the first embodiment, the internal space on one side of the sleeve 3 forms a damper chamber 18 into which hydraulic oil flows in and out as the spool 2 is displaced. The hydraulic oil flows into and out of the damper chamber 18 through a throttle 19 that penetrates the sleeve 3. The throttle 19 is provided so that the effective flow path area decreases as the hydraulic pressure increases.
Thereby, the higher the hydraulic pressure, the smaller the throttle passage flow rate.

  Here, the responsiveness to the displacement of the spool 2 (spool responsiveness) increases as the throttle passage flow rate increases, and decreases as the throttle passage flow rate decreases. On the other hand, the stability against the displacement of the spool 2 (spool stability) increases as the throttle passage flow rate decreases, and decreases as the throttle passage flow rate increases.

  Therefore, if the throttle 19 is provided as described above, the higher the hydraulic pressure, the smaller the throttle passage flow rate and the spool stability improves. Conversely, the lower the hydraulic pressure, the larger the throttle passage flow rate and the spool response. Will improve. In other words, when the hydraulic pressure is high and the spool stability decreases, the throttle flow rate decreases to compensate for the decrease in spool stability. Conversely, when the hydraulic pressure is low and the spool response decreases, the throttle flow rate increases and the spool response To compensate for the decline. As a result, it is possible to achieve both spool response and spool stability regardless of the hydraulic pressure level.

(A) is sectional drawing which shows the solenoid valve at the time of import full closure, (b) is principal part sectional drawing which shows the principal part of the solenoid valve at the time of import full closure. (A) is sectional drawing which shows the solenoid valve at the time of import half-opening, (b) is principal part sectional drawing which shows the principal part of the solenoid valve at the time of import half-opening. (A) is sectional drawing which shows the solenoid valve at the time of import full open, (b) is principal part sectional drawing which shows the principal part of the solenoid valve at the time of import full open.

Explanation of symbols

1 Solenoid valve 2 Spool 3 Sleeve 18 Damper chamber 19 Restriction 21 Internal opening

Claims (3)

In an electromagnetic valve that operates by obtaining driving force by an electromagnetic actuator and controls the flow of fluid,
A spool that receives a driving force transmitted from the electromagnetic actuator and is displaced to one side in the axial direction, and varies a displacement amount according to fluid pressure; and a sleeve that slidably accommodates the spool in the axial direction,
The internal space on one side of the sleeve is sealed by the spool, and forms a damper chamber in which fluid flows in and out with displacement of the spool.
The inflow and outflow of fluid from the damper chamber is performed through a throttle that penetrates the sleeve,
The electromagnetic valve according to claim 1, wherein the restrictor is provided so that an effective flow path area in fluid inflow and inflow through the restrictor can be varied in accordance with a displacement amount of the spool. The solenoid valve according to claim 1,
An electromagnetic valve characterized in that the correlation between the effective flow path area and the amount of displacement of the spool is varied by processing at least one of the peripheral edge of the inner opening of the throttle and the outer periphery of the spool. The solenoid valve according to claim 1 or 2,
The fluid is hydraulic oil for obtaining hydraulic pressure,
An electromagnetic valve characterized in that a displacement amount of the spool is varied in accordance with hydraulic pressure.

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