JPH0442600Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

The present invention relates to a hydraulic control device for an automatic transmission for a vehicle that does not have an electromagnetic solenoid valve for so-called speed change control.
The present invention relates to a hydraulic control system for an automatic transmission for a vehicle that is improved to reduce shift shock when shifting from each range (neutral) to a drive (D) range.

[Conventional technology]

A gear transmission mechanism and a plurality of frictional engagement devices are provided, and engagement of the frictional engagement devices is selectively switched by operating a hydraulic control device, and any one of the plurality of gears is set. Automatic transmissions for vehicles configured to achieve this are already widely known. Such automatic transmissions for vehicles generally include a shift lever operated by the driver, a vehicle speed sensor that detects the vehicle speed, and a throttle sensor that detects the throttle opening. Accordingly, the engagement state of the frictional engagement device can be automatically switched in relation to at least the vehicle speed and the throttle opening. Conventionally, in the above automatic transmission for a vehicle, when the driver performs an N-D shift operation, before the planetary gear transmission mechanism of the transmission is brought into the first gear engagement state, It is known to perform so-called squat auto control, which prevents the occurrence of shock due to sudden transmission of torque by temporarily passing through a gear position other than first gear, which has a small gear ratio. In addition, we have further improved this squat auto control so that gear ratios other than 1st gear can be smoothly engaged with a short time lag.
A device in which one brake is engaged in advance from the (neutral) position is already known (Japanese Patent Laid-Open No. 55-78845).

[Problem that the invention attempts to solve]

However, when parking, for example, when parking, turning around on a narrow road, etc.
A direct R-D or PD shift may be performed, and in such a case, there is a problem in that the conventional squat auto control does not work. Further, the above-mentioned squat auto control is set in advance by a central processing unit that receives a position signal from a shift lever operated by the driver, a throttle opening signal from a throttle sensor, a vehicle speed signal from a vehicle speed sensor, etc. This method is achieved by driving and controlling an electromagnetic solenoid valve according to a transmission pattern, and can only be used with so-called electric automatic transmissions, and cannot be used with purely hydraulic automatic transmissions. . In recent years, as front engines and front drive vehicles have become more common, engine mounts have become softer to counteract idle vibrations, and as a result, N-D
The shock when shifting tends to become larger. In order to reduce this shock, it is thought that the most effective method is to pass through a gear other than 1st gear during N-D shifting, so hydraulic control can also be used in purely hydraulic automatic transmissions. The device was desired. By the way, in a pure hydraulic automatic transmission, N→
An example of a technique designed to reduce the shock during D-shifting is disclosed in Japanese Patent Application Laid-open No. 55-142153. This technology first stops the input shaft of the automatic transmission, which was conventionally connected to the engine via a torque converter in the N range, at the same time as the shift from N to D, and then uses a delay oil passage configuration to stop the input shaft of the automatic transmission, which was previously connected to the engine via a torque converter. Oil is supplied to the frictional engagement device that forms the first gear, and when this oil pressure exceeds a predetermined value,
The oil in the frictional engagement device that had stopped the input shaft is drained and the input shaft can be rotated.
According to this technology, the input shaft, which was previously rotated together, is stopped and then the stopped output shaft is connected, thereby eliminating the shock that occurs when the input shaft suddenly stops. Can be suppressed. However, the so-called shock during N→D shift occurs when the rotating engine side is connected to the stopped output shaft side, and the input shaft is on the engine side (rotating There is not much difference whether the output shaft is connected to the output shaft side (state) or the engine side is connected to the output shaft side (stopped state). Japanese Patent Application Laid-open No. 142153/1983 is a method that replaces the conventional state, and the original N-D shock occurs at the stage when the input shaft starts rotating after being connected to the output shaft side. The problem still remained. Furthermore, since a delay circuit is employed, there is a problem in that it takes a long time to finally complete the N-D shift.

[Purpose of invention]

The present invention has been made in view of the above-mentioned conventional demands, and is not limited to the N-D shift but also the R-D shift.
It is possible to alleviate shift shock by passing through a high speed gear even during a PD shift, and it is also possible to reduce shift shock, especially in automatic transmissions that do not have an electromagnetic solenoid valve for shift control. The purpose is to provide such a hydraulic control device.

[Means to solve the problem]

The present invention includes a first frictional engagement device for achieving a first gear, and a second frictional engagement device that is engaged with the first frictional engagement device to achieve a high gear other than the first gear. a hydraulic control device for a vehicle automatic transmission, which is switched in conjunction with the position of a shift range, and when the position of the shift range is set to the forward range, the first frictional engagement device is switched; a manual valve that generates hydraulic pressure and does not generate hydraulic pressure in the first frictional engagement device when the shift range is in a parking range, neutral range, or reverse range; A first port on which hydraulic pressure to the frictional engagement device is branched and acts; a second port on which hydraulic pressure constantly generated by a pressure regulating valve acts directly;
The position is determined by the balance between the hydraulic pressure applied to the first frictional engagement device acting on the first port and the biasing force of the return spring, and when the hydraulic pressure applied to the first frictional engagement device is low, the second port and a control valve having a spool that brings the spool into communication with the second frictional engagement device and shuts it off when the high speed is reached. The purpose has been achieved. In addition, in the scope of the utility model registration request, the “first
The term "gear" refers to the lowest gear in the forward range, and the term "high gear" refers to higher gears. Therefore, the term "high speed gear" does not necessarily refer only to the so-called "second gear", which is one gear higher than the first gear.

[Effect]

In the present invention, a control valve that operates purely hydraulically is used in order to cause the transmission to go through a gear other than the first gear when an N-D shift or the like is performed. In other words, the manual valve linked to the shift lever is in a range other than forward (P,
R, N), hydraulic pressure is supplied and maintained in advance to the second frictional engagement device that engages in the high speed gear, and when the manual valve is shifted to the D range, the first gear is shifted. When the hydraulic pressure generated in the first frictional engagement device that engages in the stage reaches a predetermined pressure determined by the biasing force of the return spring, the hydraulic pressure in the second frictional engagement device that was maintained is increased. It was designed to release the As a result, after the gear is shifted to the D range, until the hydraulic pressure in the second frictional engagement device is released, a hydraulic pressure supply state for achieving the high speed gear is created, and the shift shock is adjusted accordingly. Reduced. Further, the time required to complete the N-D shift does not become long.

【Example】

Embodiments of the present invention will be described in detail below based on the drawings. FIG. 2 is a schematic block diagram showing an example of a hydraulic four-speed automatic transmission with an overdrive device. This automatic transmission includes, as its transmission section, a torque converter 10, an overdrive mechanism 12, and an underdrive mechanism 14 with three forward speeds and one reverse speed. The torque converter 10 is well known and includes a pump 16, a turbine 18, and a stator 20. Pump 16 is connected to an engine crankshaft 22, and turbine 18 is connected to a turbine shaft 24. The turbine shaft 24 serves as an output shaft of the torque converter 10 and an input shaft of the overdrive mechanism 12, and is connected to a carrier 26 of a planetary gear system in the overdrive mechanism 12. In the overdrive mechanism 12, a planetary pinion 28 rotatably supported by the carrier 26 meshes with a sun gear 30 and a ring gear 34. Also, an overdrive clutch is installed between the sun gear 30 and the carrier 26.
C ₀ and a one-way clutch F ₀ are provided, and an overdrive brake B ₀ is also provided between the sun gear 30 and a housing 32 surrounding the overdrive mechanism 12 . Ring gear 34 of overdrive mechanism 12
is connected to the input shaft 36 of the underdrive mechanism 14, and a forward clutch _C1 is provided between the input shaft 36 and the intermediate shaft 38. The underdrive mechanism 14 is provided with two rows of planetary gears, one on the front side and the other on the rear side. The front side planetary gear device is the front side,
A sun gear 42 provided on a common rear sun gear shaft 40, a planetary pinion 44 that meshes with the sun gear 42, a carrier 46 that rotatably supports the planetary pinion 44, and a ring gear 48 that meshes with the planetary pinion 44. It is composed of. Further, the rear planetary gear device includes a planetary pinion 50 that meshes with the sun gear 42, a carrier 52 that rotatably supports the planetary pinion 50, and a ring gear 54 that meshes with the planetary pinion 50. ing. A direct clutch _C2 is provided between the input shaft 36 and the sun gear shaft 40. Also, the ring gear 48 in the front planetary gear device
is connected to the intermediate shaft 38. Further, the carrier 46 in the front planetary gear device is connected to a ring gear 54 in the rear planetary gear device, and the carrier 46 and ring gear 54 are connected to an output shaft 56. Further, a first-and-reverse brake _B3 and a one-way clutch _F2 are provided between the carrier 52 and the housing 32 in the rear planetary gear unit. Further, a second brake B 2 is provided between the sun gear shaft 40 and the housing 32 via a one-way clutch F ₁ , and _{a second course brake B 1 is} provided between the sun gear shaft 40 and the housing 32 . It is provided. This automatic transmission is equipped with a transmission section as described above, and the combination of engagement of each clutch, brake, etc. as shown in FIG. 3 is performed via a hydraulic control device U to perform gear change control. Ru. FIG. 1 shows the main parts of the hydraulic control device U. In the figure, reference numeral 100 is an oil pump that sucks oil in an oil reservoir 101, pressurizes it, and discharges it; reference numeral 110 is an oil pump that regulates and outputs the basic oil pressure from this oil pump 100 to a line pressure corresponding to the throttle opening degree. The primary regulator valve (pressure regulating valve) 120 is a throttle valve that regulates and outputs a throttle pressure proportional to the throttle opening, and the symbol 130 is a throttle valve that regulates and outputs a governor pressure that is proportional to the vehicle speed. Governor valve, code 140
150 is a 1-2 shift valve that controls the first and second gear states, and 160 is a manual valve. 140 is L
When in the range, adjust the line pressure to a lower hydraulic pressure and use the first and reverse brake B ₃
A low coast modulator valve that relieves shock by reducing the hydraulic pressure acting on the
are shown respectively. Further, reference numeral 180 is a check valve, 190,2
10 is a one-way orifice, and 220 and 230 are accumulators, respectively. In the manual valve 140, in the neutral position, the line pressure applied to the port 140a does not communicate with any other port, in the drive position, the ports 140a and 140b communicate with each other, and in the second position, the port 140c is continuous, and the low Further, at this position, the port 140d is communicated, so that oil passages can be switched at each shift position. Also, in the reverse position, ports 140a and 1
40e, and port 1 in the parking position.
40a is adapted to be closed. Here, reference numeral 170 is a control valve for performing squat control in the present invention. As shown in detail in FIG. 4, this control valve 170 includes a spool 170d on which a spring 170a is disposed and two lands 170b and 170c are formed. The spool 170d has line pressure applied from the primary regulator valve 110 to opposing faces 170e and 170f of the lands 170b and 170c through a port (second port) 170h, and a port (first port) Hydraulic pressure P _C1 directed toward forward clutch C ₁ (frictional engagement device for forming the first gear) is applied to the other face 170g of land 170b via 170j. As a result, until the hydraulic pressure P _C1 directed toward the forward clutch C ₁ reaches the predetermined pressure Pcs set in relation to the mounting load of the spring 170a, the state is in the upper side of FIG. 4, and the primary regulator valve 110 The line pressure supplied from the check valve 180 is output from the port 170i to the check valve 180. Further, when the hydraulic pressure P _C1 directed to the forward clutch C ₁ exceeds the predetermined pressure Pcs, the pressure overcomes the mounting load of the spring 170a and becomes the state shown in the lower side of FIG. Line pressure is cut off by land 170b, and output port 170i is placed in an open state. Next, the operation of this embodiment will be explained. When the manual valve 140 is in each of the N, R, and P positions, the forward clutch hydraulic pressure P _C1 is not generated, so the control valve 170 is in the upper state in FIG. 4, and the ports 170h and 17
0i, the line pressure from the primary regulator valve 110 is applied to the check valve 180, and further passes through the one-way orifice 210 to the second brake _B2 (frictional engagement device for forming the second gear). ), the second brake _B2 maintains the engaged state. Here, for example, when an N-D shift is performed, the ports 140a and 140 of the manual valve 140
Since the line pressure is in communication with the accumulator 220 and the forward clutch _C1 through the one-way orifice 190, the actuation of the accumulator 220 causes the forward clutch to open as shown in FIG. The oil pressure P _c1 of C ₁ rises slowly. This oil pressure P _C1 is the control valve 170
However, until the hydraulic pressure P _C1 reaches the predetermined pressure Pcs, the control valve 170 is pressed to the left side in the drawing by the spring 170a (the upper state in Fig. 4), so the second brake B ₂
remains engaged. However, when the hydraulic pressure P _C1 of the forward clutch C ₁ further increases and reaches a predetermined pressure Pcs, the control valve 170 switches to the state shown in the lower part of the drawing, so the hydraulic pressure of the second brake B ₂ is drained, and the second brake B 2 is drained. _B2 is in the released state and the automatic transmission is in the first gear. This situation is shown in FIG.
The figure shows that the forward clutch oil pressure P _C1 is the predetermined pressure Pcs
Since the second brake hydraulic pressure P _B2 is being supplied until , the peak torque of the output shaft, which conventionally occurs as shown by the broken line, is alleviated as shown by the solid line. Due to the relationship between the forward clutch hydraulic pressure P _C1 and the predetermined pressure Pcs determined by the spring 170a, the action of changing the second brake _B2 from the engaged state to the released state is completely absent even in R-D and P-D. This is done in the same way, and the shock is reduced in each case. Note that in the D range, the line pressure also acts on the port 150b of the 1-2 shift valve 150. As is well known, the 1-2 shift valve 150 controls the governor pressure applied to the port 150a and the
Throttle pressure and spring 150 applied to 50d
Since the switch is made based on the balance of the forces of
The second brake _B2 is in a released state. Also, in the second gear, the state is on the right side of the drawing, so port 1
50b and 150c are in communication, and the line pressure is passed through the check valve 180 to the one-way orifice 2.
10, the hydraulic pressure is gradually increased by the operation of the accumulator 230, and the second brake _B2 is applied, and the second brake _B2 is slowly engaged. In the L range, manual valve 140
Line pressure is also generated at the port 140d. This line pressure is the low coast modulator valve 1
After the pressure is regulated to a predetermined oil pressure by 60, 1-2
Ports 150f and 1 of shift valve 150
Applied for 50h. Therefore, due to the balance between the governor pressure applied to port 150a and the low coast modulator pressure applied to ports 150f and 150h,
If the downward force is strong, the vehicle will be in the first gear state. On the other hand, since the ports 150f and 150e communicate with each other, low coast modulator pressure is applied to the first and reverse brake _B3 , and the first and reverse brake _B3 is engaged. The brakes become effective. In the above embodiment, the so-called "second gear", which is one gear higher than the first gear, is used as the "high speed gear".
However, the "high speed" in the present invention does not necessarily have to be the "second"speed; for example, the same effect can be obtained even if it is the "third" speed. Furthermore, in the present invention, the second frictional engagement device that engages in the high speed stage is engaged in each of the N, R, and P ranges, but for example, engagement of the second frictional engagement device in the R range may be problematic. In this case, the one-way clutch disposed in series with the second frictional engagement device as in the above embodiment
This can be dealt with by simple means such as providing F ₁ . Note that the one-way clutch _F1 of this embodiment has been conventionally provided for another purpose, and is not newly provided for the present invention. Furthermore, as is clear from the embodiments described above, the control valve for the above-mentioned squat control can be constructed of the same valve as the low-coast modulator valve, for example, so that cost reduction can be achieved.

[Effect of the idea]

As explained above, according to the present invention, it is possible to reduce the shift shock not only during the N-D shift but also during the R-D and P-D shifts. An excellent effect can be obtained in that the control can be controlled purely hydraulically by adding one control valve. Further, since this control valve can be the same as, for example, a low-cost modulator valve, it can be manufactured at extremely low cost, and an increase in the cost for the above-mentioned control can be suppressed.

[Brief explanation of drawings]

FIG. 1 is a main hydraulic circuit diagram showing an embodiment of a hydraulic control device for a vehicle automatic transmission according to the present invention, and FIG. 2 is a transmission diagram of a vehicle automatic transmission to which the above embodiment is applied. Skeleton diagram showing the section,
FIG. 3 is a diagram showing the engaged/combined state of each frictional engagement device, FIG. 4 is an enlarged view of the control valve in FIG. 1, and FIG. 5 is a diagram showing the hydraulic pressure in the above embodiment. FIG. 3 is a diagram showing the relationship with output shaft torque along the time axis. C ₁ ... Forward clutch (first friction engagement device), B ₂ ... Second brake (second friction engagement device), F ₁ ... One-way clutch, 140 ... Manual valve, 150 ... 1- 2 shift valve, 1
70...(Squaw auto) control valve.

Claims (1)

[Claims for Utility Model Registration] A first frictional engagement device for achieving a first gear; and a first frictional engagement device for achieving a high gear other than the first gear by being engaged with the first frictional engagement device. A hydraulic control device for a vehicle automatic transmission comprising a second frictional engagement device, wherein the first frictional engagement device is switched in conjunction with a shift range position, and when the shift range position is set to the forward range. In addition to generating hydraulic pressure to the coupling device,
a manual valve that does not generate hydraulic pressure in the first frictional engagement device when the shift range is in the parking range, neutral range, or reverse range; and a manual valve that does not generate hydraulic pressure in the first frictional engagement device from the manual valve to the first frictional engagement device. A first port where hydraulic pressure is branched and acts;
A second port on which hydraulic pressure constantly generated by a pressure regulating valve directly acts, and a first frictional engagement device that acts on the first port are positioned by the balance between the hydraulic pressure and the biasing force of a return spring,
When the oil pressure to the first frictional engagement device is low, the second
A control valve having a spool that brings the port and the second friction engagement device into communication and shuts it off when the temperature is high, thereby making it possible to achieve the first gear via the high speed gear. Features: Hydraulic control device for automatic transmissions for vehicles.