JP6659068B2 - Hydraulic control device for automatic transmission - Google Patents

Description

  The present invention relates to a hydraulic control device for an automatic transmission in which a response delay when a manual valve linked to a select lever is switched from a stop range to a travel range is improved and a friction engagement element is operated with good responsiveness.

  In automatic transmissions such as continuously variable transmissions (CVTs) and multi-stage transmissions, the hydraulic pressure supplied to and discharged from a plurality of frictional engagement elements such as clutches and brakes is controlled by a manual valve linked to a select lever. The switching operation of each range (P, R, N, D) is realized.

  In this case, when the select lever is set to a neutral (N) range, as disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2013-24327), a manual valve interlocked with the selector lever is connected to a reverse brake and a forward brake. The hydraulic pressure supplied to the clutch is drained to open the clutch. Then, when the select lever is set to the reverse (R) range from this state, the operating pressure is supplied to the reverse brake through the manual valve and the reverse brake is engaged, and the output from the engine is changed by the forward / reverse switching device of the CVT or the planetary gear device. The rotation is transmitted in reverse by the multi-stage transmission configured.

JP 2013-24327 A

  By the way, when the select lever is switched from the N range (stop range) to the R range (travel range) to supply the working pressure to the reverse brake (friction engagement element), the working pressure supplied to the working chamber of the reverse brake is already Since it is drained, first, the working chamber is filled with working pressure, and then the reverse piston is moved against the urging force of the return spring, and the reverse brake is engaged.

  Therefore, in the technique disclosed in the above-mentioned document, there is a certain time lag from when the select lever is set from the N range to the R range until the driving force is actually reversed and output. As a result, even if the driver switches the select lever from the N range to the R range and depresses the accelerator pedal, the vehicle does not immediately reverse, so that there is a problem that the driver may feel uncomfortable due to a delay in response.

  In view of the above circumstances, the present invention can improve a response delay when the driver switches the select lever from a stop range such as a neutral range to a travel range such as a reverse range, and can reduce a sense of discomfort given to the driver. An object of the present invention is to provide a hydraulic control device for an automatic transmission.

  The hydraulic control device for an automatic transmission according to the present invention includes a friction engagement element that is engaged at least in the travel range and is released in the stop range, and is connected to the select lever so that the select lever is set to the travel range. A manual valve for supplying an operating pressure to an operating chamber of the friction engagement element, and draining the operating pressure supplied to the operating chamber when the select lever is set to the stop range; and A first oil path for supplying operating pressure from the manual valve to the working chamber when the select lever is set to the travel range and the select lever is set to the travel range, and a first oil path is arranged in parallel with the first oil path. When the manual valve communicates with the working chamber and the select lever is set to the stop range, the manual valve is A second oil passage that supplies the operating pressure of the first oil passage to the working chamber to drain from the first oil passage, a pressure reducing unit interposed in the first oil passage, and a second oil passage that is interposed in the second oil passage. Oil passage opening / closing means for permitting the flow of the operating pressure from the manual valve to the working chamber and blocking the flow in the reverse direction.

  According to the present invention, when the select lever is set to the stop range, the operating pressure from the manual valve is supplied to the working chamber of the friction engagement element via the second oil passage and the oil passage opening / closing means, and the drain is drained from the first oil passage. Is done. At this time, since a pre-pressure that reduces the working pressure is generated in the working chamber by the pressure reducing means interposed in the first oil passage, when the driver switches the select lever to the travel range thereafter, In this configuration, the frictional engagement element can be immediately engaged, the response delay can be improved, and the driver's uncomfortable feeling can be reduced.

Schematic configuration diagram showing the power transmission system of the continuously variable transmission Hydraulic circuit diagram of manual valve and pressure regulating valve Hydraulic circuit diagram between manual valve and reverse brake

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a continuously variable transmission (CVT) is shown as an example of the automatic transmission.

  In FIG. 1, reference numeral 1 denotes an engine. An output shaft 2 of the engine 1 is connected to a drive shaft 6 supporting a drive wheel 5 via a continuously variable transmission 3 and a final reduction gear 4. The continuously variable transmission 3 includes a torque converter 7, a forward / reverse switching device 8, and a continuously variable transmission (CVT) 9 from the input side.

  The output shaft 2 of the engine 1 is connected to an impeller 7a of a torque converter 7, and a turbine 7b of the torque converter 7 is connected to a planetary input shaft 8a of a forward / reverse switching device 8. Reference numeral 7c denotes a lock-up clutch, and 7d denotes a mechanical oil pump using the engine 1 as a drive source.

  The forward / reverse switching device 8 includes a double pinion type planetary gear 10 therein, and a planetary input shaft 8a is connected to a sun gear 10a of the planetary gear 10. Further, the sun gear 10a and a ring gear 10c disposed on the outer periphery of the sun gear 10a are connected to each other via a planetary pinion 10d, and a carrier 10b supporting the planetary pinion 10d is connected to a primary input shaft 9a of the CVT 9. It is connected to.

  Reference numerals 11 and 12 denote a forward clutch and a reverse brake as friction engagement elements. The forward clutch 11 is interposed between the carrier 10b and the planetary input shaft 8a, while the reverse brake 12 is connected to the ring gear 10c and the transmission. It is interposed between the case 3a.

  When both the forward clutch 11 and the reverse brake 12 are in the released state, a neutral state is established in which power transmission between the planetary input shaft 8a and the primary input shaft 9a is interrupted. In this state, when the forward clutch 11 is engaged, the planetary input shaft 8a and the primary input shaft 9a are directly connected, and the planetary gear 10 rotates integrally. On the other hand, when the forward clutch 11 is released and the reverse brake 12 is engaged, the ring gear 10c is fixed to the transmission case 3a, the planetary pinion 10d is rotated by the rotation of the sun gear 10a, and the carrier 10b is decelerated to a predetermined speed. The drive force is reversed, and this driving force is output to the primary input shaft 9a via the carrier 10b.

  A primary pulley 9b is axially mounted on the primary input shaft 9a of the CVT 9, a secondary pulley 9c opposed to the primary pulley 9b is axially mounted on a secondary output shaft 9d, and a belt 9e is wound around the pulleys 9b and 9c. Have been. A primary hydraulic chamber 9f and a secondary hydraulic chamber 9g are provided on the movable sheave side of each of the pulleys 9b and 9c, and the pressure of hydraulic oil supplied to each of the hydraulic chambers 9f and 9g (hereinafter abbreviated as "operating pressure"). Thus, the groove widths of both pulleys 9b and 9c are set to be in an inversely proportional state, and the shift control is performed. A secondary output shaft 9d of the CVT 9 is connected to a differential device 4b which is mounted on the drive shaft 6 via a reduction gear train 4a of the final reduction device 4.

  The forward clutch 11 and the reverse brake 12 are engaged or released by hydraulic control. As shown in FIG. 2, a forward clutch oil passage 11a is connected to the forward clutch 11. Further, a first reverse brake oil passage 12a as a first oil passage and a second reverse brake oil passage 12b as a second oil passage are connected to the reverse brake 12 in parallel.

  An orifice 13 is provided in the first reverse brake oil passage 12a as pressure reducing means for limiting the flow rate of hydraulic oil passing through the first reverse brake oil passage 12a by passage resistance. A check valve 14 as an oil passage opening / closing means is interposed in 12b.

  The check valve 14 allows the flow of hydraulic oil from the manual valve 15 described below in the direction of the reverse brake 12 and shuts off the flow in the reverse direction. As shown in FIG. A return spring 14b that constantly urges the check ball 14a in the valve closing direction.

  Supply and discharge of hydraulic pressure to and from the forward clutch 11 and the reverse brake 12 are performed by the operation of the manual valve 15. The manual valve 15 is a 6-port, 4-position switching valve, and is switched in conjunction with the operation of a select lever 16a provided in a select operation section 16 provided on the center console of the vehicle. The select lever 16a can be set to a drive (D) range and a reverse (R) range as a travel range, a neutral (N) range and a parking (P) range as a stop range by a driver's operation. is there.

  Further, the manual valve 15 and the pressure regulating valve 17 are freely communicable via a pressure regulating oil passage 18a and a pressure regulating branch oil passage 18b branched from the pressure regulating oil passage 18a. The pressure regulating valve 17 is a three-port two-position switching valve that outputs an operating pressure adjusted using the line pressure from the oil pump 7d as a source pressure to the manual valve 15, and the solenoid 17a is connected to a controller (not shown). The controller operates the pressure regulating valve 17 via the solenoid 17a so as to generate a predetermined operating pressure. However, since the pressure regulation control of the pressure regulating valve 17 is well known, a detailed description is omitted. Reference numeral 17b is a drain oil passage.

  When the select lever 16a is set to the N range, the pressure adjusting oil passage 18a is communicated with the second reverse brake oil passage 12b, and the first reverse brake oil passage 12a and the forward clutch oil passage 11a are connected to the drain oil passage 18c. Communicated. Therefore, as shown in FIG. 3A, the hydraulic oil from the pressure regulating branch oil passage 18b is interposed in the second reverse brake oil passage 12b from between the lands 15b and 15c formed on the spool 15a of the manual valve 15. The check valve 14 is opened to flow into the brake working chamber 12c of the reverse brake 12 and flow to the first reverse brake oil passage 12a. An orifice 13 is interposed in the first reverse brake oil passage 12a, and the return flow rate is limited by the passage resistance of the first reverse brake oil passage 12a. However, against the urging force of a return spring (not shown) that urges the piston 14d in the opening direction, a pressure is generated that does not operate in the fastening direction.

  This preload is set to a maximum pressure that does not exceed the urging force of the return spring, and is set by adjusting the passage resistance of the orifice 13, that is, the cross-sectional area. Therefore, when the driver sets the select lever 16a to the N range, a preload is generated in the brake working chamber 12c, and the reverse brake 12 is brought into a standby state where the fastening operation can be immediately performed with a slight increase in pressure.

  On the other hand, when the select lever 16a is set to the R range, the pressure regulation branch oil passage 18b is connected to the first reverse brake oil passage 12a, and the forward clutch oil passage 11a is connected to the drain oil passage 18c. As shown in FIG. 3B, the check valve 14 interposed in the second reverse brake oil passage 12b closes, and the flow of the hydraulic oil flowing from the reverse brake 12 side is interrupted. The operating pressure of the chamber 12c gradually increases.

  Next, the operation of the present embodiment having such a configuration will be described. When the driver sets the select lever 16a to the N range, as shown in FIG. 3A, the spool 15a of the manual valve 15 causes the operating pressure from the pressure regulating valve 17 to pass through the lands 15b and 15c facing each other. The discharged pressure regulating oil passage 18a and the second reverse brake oil passage 12b communicate with each other. As shown in FIG. 2, the first reverse brake oil passage 12a and the forward clutch oil passage 11a communicate with the drain oil passage 18c.

  Then, the operating pressure supplied to the forward clutch 11 is drained and released. On the other hand, as shown in FIG. 3A, the operating pressure supplied to the second reverse brake oil passage 12b causes the check ball 14a of the check valve 14 to open against the urging force of the return spring 14b. Flows into the brake operation chamber 12c of the reverse brake 12.

  The operating pressure flowing into the brake working chamber 12c flows through the first reverse brake oil passage 12a. However, since the orifice 13 is interposed in the first reverse brake oil passage 12a, the flow rate is restricted, and the brake pressure is reduced. In the working chamber 12c, a pre-pressure is generated in which the working pressure is reduced to a predetermined value by the passage resistance of the orifice 13. Since this preload is set to the maximum pressure that does not exceed the urging force of the return spring, a standby state is established in which the fastening operation can be performed immediately with a slight increase in pressure. In this state, since both the forward clutch 11 and the reverse brake 12 are released, the forward / reverse switching device 8 is in the neutral state.

  Thereafter, when the driver operates the select lever 16a to switch the select position from the N range to the D range, the supply of the operating pressure from the second reverse brake oil passage 12b to the brake operating chamber 12c is cut off, and the One reverse brake oil passage 12a communicates with drain oil passage 18c. As a result, the operating pressure of the brake operation chamber 12c is drained to the drain oil passage 18c via the first reverse brake oil passage 12a, and the preload for urging the brake piston 12d is released.

  Further, since the forward clutch 11 and the pressure regulating oil passage 18a are communicated with each other, the working pressure obtained by regulating the line pressure by the pressure regulating valve 17 is supplied to the forward clutch 11, and the forward clutch 11 is engaged. As a result, the driving force from the engine 1 is transmitted to the CVT 9 via the torque converter 7 and the forward / reverse switching device 8, thereby enabling forward traveling.

  On the other hand, when the driver operates the select lever 16a to switch the select position from the N range to the R range, the forward clutch oil passage 11a is connected to the drain oil passage 18c as shown in FIG. The supplied hydraulic oil is drained and released. At the same time, as shown in FIG. 3B, the land 15b provided on the spool 15a of the manual valve 15 shuts off the connection between the pressure regulating oil passage 18a and the second reverse brake oil passage 12b. Further, the pressure regulating branch oil passage 18b and the first reverse brake oil passage 12a are communicated via the land 15b and the land 15c facing each other.

  As a result, the check ball 14a of the check valve 14 is closed by receiving the urging force of the return spring 14b, and the working oil is supplied to the brake working chamber 12c through the first reverse brake oil passage 12a. Therefore, the flow of the working oil flowing from the first reverse brake oil passage 12a into the brake working chamber 12c in the direction of the second reverse brake oil passage 12b is blocked by the check valve 14, so that the working oil stays in the brake working chamber 12c. Then, the internal pressure (operating pressure) gradually increases, and the brake piston 12d causes the reverse brake 12 to engage.

  When the reverse brake 12 is engaged, the forward / reverse switching device 8 reversely rotates, and the driving force from the engine 1 is transmitted to the CVT 9 as the reverse driving force decelerated by the forward / reverse switching device 8 to a predetermined value, and the vehicle travels in reverse. Traveling becomes possible.

  At this time, when the brake piston 12d is in the N range, it can be started to move in the fastening direction with a slight increase in pressure by the preload supplied to the brake operation chamber 12c. When the select lever 16a is set to the R range, the brake 12 is immediately engaged by the operating pressure supplied to the brake operating chamber 12c. As a result, the response delay when the driver switches the select lever 16a from the N range to the R range is improved, and the uncomfortable feeling given to the driver can be reduced.

  When the select lever 16a is switched from the R range to the P range, as shown in FIG. 2, both the forward clutch oil passage 11a and the first reverse brake oil passage 12a communicate with the drain oil passage 18c. The hydraulic oil supplied to the motor 11 and the reverse brake 12 is drained and released, and the forward / reverse switching device 8 enters an idle state.

  As described above, according to the present embodiment, when the select lever 16b is set to the N range, a preload of the maximum pressure capable of maintaining the reverse brake 12 in the open state is generated in the brake operating chamber 12c of the reverse brake 12. Therefore, when the select lever 16b is switched to the R range from this state, the brake piston 12d is immediately activated by a slight pressure increase, and the reverse brake 12 is engaged.

  As a result, the response delay immediately after the select lever 16a is set to the R range is improved. For example, in the case of turning back at the time of reverse parking in a parking lot, the select lever 16a is set to the R range from the D range through the N range. Thus, it is possible to smoothly switch back from forward to reverse, and to reduce the discomfort given to the driver.

  The present invention is not limited to the above-described embodiment. For example, the automatic transmission may be a multi-stage transmission, and the present invention can be applied to a manual valve of the multi-stage transmission.

1. Engine,
3. Continuously variable transmission,
7d ... oil pump,
8 forward / reverse switching device
9 ... continuously variable transmission,
11 ... forward clutch,
11a: forward clutch oil passage,
12 ... Reverse brake,
12a: first reverse brake oil passage,
12b: second reverse brake oil passage,
12c: brake working chamber,
12d ... brake piston,
13 ... orifice,
14. Check valve,
14a ... check ball,
14b ... return spring,
15 Manual valve,
15a ... spool,
15b, 15c ... land,
16a ... Select lever,
17 ... pressure regulating valve,
18a: Pressure adjusting oil passage,
18b ... pressure regulation branch oil passage

Claims (4)

A friction engagement element that is fastened at least in the traveling range and released in the stop range;
When the select lever is set to the travel range, the operating pressure is supplied to the working chamber of the friction engagement element, and when the select lever is set to the stop range, the operation is performed. A manual valve for draining the operating pressure supplied to the chamber,
A first oil passage that communicates the manual valve with the working chamber and supplies operating pressure from the manual valve to the working chamber when the select lever is set to the travel range;
When the select lever is set to the stop range, the operating pressure from the manual valve is supplied to the working chamber while the manual valve and the working chamber are connected in parallel with the first oil passage. A second oil passage for draining from the first oil passage,
Decompression means interposed in the first oil passage;
An oil passage opening / closing means interposed in the second oil passage to allow a flow of operating pressure from the manual valve to the working chamber and to block a flow in a reverse direction. Hydraulic control device.   The pressure reducing means reduces the operating pressure supplied to the working chamber when the select lever is set in the stop range to a pressure at which the piston of the friction engagement element does not operate in the fastening direction against the urging force of the return spring. The hydraulic pressure control device for an automatic transmission according to claim 1, wherein the pressure is reduced to a maximum pressure. 3. The hydraulic pressure control device for an automatic transmission according to claim 2, wherein said pressure reducing means is an orifice, and reduces the working pressure supplied to said working chamber by a resistance passing through said orifice. The running range is a reverse range,
The hydraulic control device for an automatic transmission according to any one of claims 1 to 3, wherein the stop range is a neutral range.

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