JPH05593Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention is a hydraulic control device for an automatic transmission of a vehicle, etc., specifically, detects the roll of a power unit and controls the hydraulic pressure supplied to a friction element. The present invention relates to a hydraulic control device for an automatic transmission that stabilizes vehicle behavior when starting.

(Conventional technology) In recent years, with the increasing number of automobiles equipped with automatic transmissions, in addition to the conventional ease of driving operation, there has been a demand for improved so-called driving feeling, as typified by reduction in shift shock. There is a tendency to In particular, since the load torque is large at the time of starting, the sudden connection between the load torque and the drive torque causes a large pitching motion in the vehicle body, causing discomfort to the driver.

As an example of a conventional hydraulic control device for an automatic transmission that aims to reduce the shift shock at the time of starting, there is one shown in FIG. 7, for example.

In FIG. 7, when the shift lever (not shown) is operated, high-pressure hydraulic oil is supplied to the pressure receiving chamber 3 of the accumulator 2 through the oil passage 1, and this oil pressure causes the piston 4 to resist the biasing force of the spring 5. 7th
It is pushed down in the figure. As a result, the working oil pressure in the oil passage 1 exhibits a change characteristic in which it gradually increases from approximately zero following the downward stroke of the piston 4, and returns to the supplied working oil pressure after a predetermined period of time. Therefore, the friction elements (not shown) are gradually engaged in accordance with the changing characteristics of the working oil pressure, thereby avoiding a sudden connection of load torque and reducing the shift shock at the time of starting. By the way, in this conventional method, the speed at which the hydraulic pressure rises is slowed down to reduce the shift shock, which takes a long time to complete the shift, resulting in a so-called time lag, which causes discomfort to the driver. was giving. Further, since the above-mentioned change characteristic of the working oil pressure is determined by the spring constant of the spring 5, its control mode is extremely limited.

Therefore, the present applicant has previously proposed a hydraulic control device for an automatic transmission as shown in Fig. 8 (patent application
60-197465). In FIG. 8, when a shift lever (not shown) is operated, the high pressure hydraulic oil supplied to the oil passage 11 flows into the pressure receiving chamber 13 via the orifice 12, and the oil pressure at the initial stage of supply becomes approximately zero.
Furthermore, with an increase in the amount of oil accumulated in the pressure receiving chamber 13,
The working oil pressure in the oil passage 11 gradually increases, and the friction elements (not shown) are gradually engaged.

On the other hand, the operation of the shift lever is detected by the inhibitor switch 14, and after a predetermined timing is set in the control circuit 15, the actuator 16 is energized to open the valve body 17. As a result, the working oil pressure in the oil passage 11 is reduced to a predetermined pressure determined by the orifice 12, and this pressure reduction period is controlled by the valve opening period of the valve body 17.
That is, by appropriately setting the timing of the control circuit 15 and the orifice diameter of the orifice 12, the hydraulic pressure supplied to the friction element of the friction engagement mechanism can be temporarily reduced. Here, the dynamic friction coefficient μ of the friction element increases non-linearly as the friction element transitions from relative rotation to integral rotation, and records the maximum value just before reaching integral rotation, but the engagement hydraulic pressure is temporarily reduced. By reducing
This increase in the dynamic friction coefficient μ can be suppressed,
As shown in FIG. 9, it is possible to avoid the output shaft torque fluctuation of the automatic transmission that occurs due to the increase in the dynamic friction coefficient μ, and to reduce the shift shock. Further, since the time lag is experienced by the above-mentioned predetermined time _t1 , by setting this to a desired value, the driving feeling can be improved and the range of control modes can be expanded.

(Problem to be solved by the invention) However, in the case of the hydraulic control device for the automatic transmission of the prior application, the shift operation of the shift lever is detected, and the hydraulic pressure is controlled based on this detection timing. Because the structure was configured to perform so-called open-loop control, the control mode did not match actual operating conditions. For example, when the driving range was selected after being in the non-driving range for a long time, the oil The amount of hydraulic oil remaining on the road is small at first, and then increases rapidly as the driving range is selected. On the other hand, if a shift operation is performed in which the non-driving range is selected from the driving range and then the driving range is selected again immediately after, the new hydraulic oil may be replaced while most of the hydraulic oil remains in the oil passage. Hydraulic oil is supplied.

As the amount of hydraulic oil remaining in the oil passage varies depending on the length of time the non-traveling range is selected, the rise timing of the hydraulic pressure becomes unstable, causing friction as shown in Figure 5. There was a problem in that the element engagement time (that is, the torque rise time) varied, which worsened the driving feeling.

(Purpose of the invention) Therefore, the present invention focuses on the fact that the torque fluctuation of the output shaft, which causes the shift shock, appears as a relative displacement between the power unit and the power unit support, and operates based on this relative displacement. By controlling the oil pressure, the aim is to complete so-called closed-loop control, perform control corresponding to actual driving conditions, reduce shift shock, and improve driving feeling.

(Means for Solving the Problems) In order to achieve the above-mentioned purpose, the hydraulic control device for an automatic transmission according to the present invention opens an oil passage that supplies hydraulic pressure to a frictional engagement mechanism that switches gear states to a drain port. or a control valve that opens and closes to shut off the
Hydraulic control of an automatic transmission, comprising: a control means for outputting a control signal to the control valve to open the control valve and temporarily lower the engagement hydraulic pressure during the engagement process of the frictional engagement mechanism. The apparatus is provided with displacement detection means for detecting relative displacement between the power unit and the power unit support, a detection signal from the displacement detection means is input to the control means, and the control means The control valve is characterized in that the control valve is opened based on a point in time when a predetermined displacement is detected.

(Function) In the present invention, the initial fluctuation in the output shaft torque that occurs with the engagement of the frictional engagement mechanism is detected as a relative displacement between the power unit and the power unit support, and a predetermined displacement is detected. The control timing of the hydraulic pressure is set based on the point in time. Therefore, an excessive shift shock is avoided, and the occurrence of pitching motion of the vehicle body is effectively prevented.

(Example) Hereinafter, the present invention will be explained based on the drawings.

FIG. 1 is a diagram showing a first embodiment of a hydraulic control device for an automatic transmission according to the present invention. In the same figure,
41 is a power unit. power unit 4
1 is supported by a vehicle body (power unit support) 42 via an elastic mount (not shown), and a reflection plate 43 is attached to a predetermined outer surface 41a of the power unit 41. Also, the vehicle body 4 facing the reflector 43
2, a light emitter 44 and a light receiver 45 are disposed, and the positional relationship between the reflecting plate 43, the light emitter 44, and the light receiver 45 is such that light is not transmitted to the light receiver 45 during normal operation (when no shift shock occurs). It is determined that when the power unit is not hit and the power unit rolls (when a shift shock occurs), the light will hit the light receiver 45. That is, from the reflective surface end 43a of the reflective plate 43 in the direction of the arrow indicated by the symbol A in FIG. 1 (roll direction)
A point a predetermined distance away (hereinafter referred to as the roll detection point) is defined as point X, and the positions of the light emitter 44 and the light receiver 45 are defined as points Y and Z, respectively.The reflective surface 43b of the reflector plate 43 When rolled, it will be placed perpendicular to the line that bisects ∠YZ.

Note that the light emitting device 44 includes an LED (Light Emitting
Similarly, a photovoltaic solid state light receiving element such as a phototransistor or a photodiode is used for the light receiver 45.

The light emitter 44 receives electric power Ld from the detection circuit 46 and emits light, and the light receiver 45 receives the light from the light emitter 44 when the reflecting plate 43 reaches the roll detection point and outputs a photodetection signal Ps to the detection circuit 46. do. Note that the reflecting plate 43, the light emitter 44, the light receiver 45, and the detection circuit 46 collectively constitute a displacement detection means. The detection circuit 46 shapes the waveform of the photodetection signal Ps and outputs the detection signal Pr to the control circuit (control means) 47, and the control circuit 47 outputs the control signal Sa to the actuator (control means) at a predetermined control timing based on the detection signal Pr. control valve) 48. The actuator 48 is energized while the control signal Sa is being input to communicate the pressure receiving chamber 49 and the drain port 50, and thereby the drain port 50 communicates with the oil passage 52 via the orifice 51. The actuator 48, pressure receiving chamber 49, drain port 50 and orifice 51 together constitute hydraulic control means. One side 52a of the oil passage 52 is connected to an output port of a manual valve that operates in conjunction with a shift lever (not shown), and the other side 52b is connected to a friction element (friction engagement mechanism) not shown. This friction element selects the gear stage of a gear transmission mechanism (not shown) and determines its gear ratio.

Next, the effect will be explained.

When the friction elements of the automatic transmission are engaged at the time of starting, a reaction force against the increase in output shaft torque acts on the power unit, causing the unit to roll in the direction of the reaction force. This amount of roll becomes even more noticeable especially in vehicles where the power unit is installed horizontally, as the direction of acceleration acting on the vehicle body is the same as the direction of roll, which significantly worsens the driving feeling when starting. let That is, when the above-mentioned reaction force acts on the power unit 41, the power unit 41 rolls in the direction of the arrow shown by the symbol A in FIG. do.

On the other hand, a light emitter 44 is provided on the vehicle body 42 facing the reflection plate 43, and the light emitter 44 emits converged light toward the roll detection point. Therefore, when the reflective surface 43b of the reflective plate 43 reaches the roll detection point, the light from the light emitter 44 is reflected on the reflective surface 43b and is received by the light receiver 45 located on the reflected optical axis. The received light is converted into light/voltage by the photoreceiver 45, and a photodetection signal Ps is generated.
The signal is output to the detection circuit 46 as a signal. Detection circuit 46
Then, the photodetection signal Ps is compared with a predetermined reference level, and only a true signal exceeding the reference level is outputted to the control circuit 47 as a detection signal Pr indicating the occurrence of a shift shock.

Furthermore, the control circuit 47 generates an actuator control signal having a predetermined pulse width d after a predetermined time τ from the rise of the detection signal Pr, as shown in FIG. 6b.
Sa is output to the generated actuator 48. While this signal is input, the actuator 48 is energized to communicate the pressure receiving chamber 49 and the drain port 50, and causes the hydraulic oil in the oil passage 52 to flow out through the orifice 51 and the pressure receiving chamber 49. Therefore, the working oil pressure in the oil passage 52 decreases, and the fastening oil pressure is maintained at a predetermined level as shown in FIG. 6c.
The fastening force of the friction element is relaxed. As a result, the shift shock is reduced, the behavior of the vehicle body when starting is stabilized, and the driving feeling is improved.

In this way, in this embodiment, a sudden change in the output shaft torque → roll detection of the power unit →
Since we have completed so-called closed-loop control, which includes controlling the hydraulic pressure → alleviating the engagement force of friction elements → suppressing fluctuations in the output shaft torque, we can perform effective control that corresponds to actual operating conditions. .
Furthermore, since rapid fluctuations in the output shaft torque are detected as rolls of the power unit, this method is superior in terms of cost compared to methods that directly measure the output shaft torque.

FIGS. 2 and 3 are diagrams showing a second embodiment of the hydraulic control system for an automatic transmission according to the present invention, and are examples in which a mechanical switch is used to detect the roll of the power unit. In addition, in explaining this example,
Components that are the same as those in the first embodiment are given the same reference numerals and their explanations will be omitted.

In FIG. 2, a power unit 41 and a vehicle body 4 are shown.
2, a displacement detection switch 62 is interposed via connecting members 60 and 61. As details of the displacement detection switch 62 are shown in FIG. 3, a hook 64 is fixed to one side of a switch case 63, and a hook 65 is slidably inserted to the other side. A plate 66 is fixed to the shaft end of the hook 65, and one end of a spring 67 is locked onto this plate 66. Further, a movable contact 68 is locked to the other end of the spring 67, and this movable contact 68
The fixed side contact 6 is placed on the switch case 63 facing the
9 and 70 are arranged. Each fixed side contact 69, 70
Lead wires 71 and 72 are connected to these leads, respectively, and are connected to an external circuit via these lead wires 71 and 72. That is, as shown in FIG. 2, the lead wires 71 and 72 are connected to one end of the resistor R and the + side of the power supply V, respectively, and
The other end of the resistor R and the negative side of the power supply V are connected to each other. The displacement detection switch 62, lead wires 71, 72, resistor R and power supply V together constitute displacement detection means.

In the above configuration, when a roll occurs in the power unit 41 in the direction of the arrow shown by reference numeral B in FIG. 2, the movable contact 68 of the displacement detection switch 62 comes into contact with the fixed contacts 69 and 70. As a result, the power supply V, lead wire 71, fixed side contact 69, movable side contact 68, fixed side contact 70, lead wire 72, resistor R,
A closed circuit is formed through the power supply V, through which a current i flows. Current i is applied to resistor R by voltage e (e=i
xR), and this voltage e is input to the control circuit 47 as a signal indicating roll detection (that is, shift shock detection).

In this way, the roll of the power unit 41 can be detected in this embodiment as well as in the first embodiment, and by performing predetermined control based on this, the same effects as in the first embodiment can be obtained. be able to. Note that, as an advantage unique to this embodiment, since the displacement detection switch 62 has a simple structure, it can be manufactured at low cost, and costs can be reduced.

FIG. 4 is a diagram showing a third embodiment of the hydraulic control system for an automatic transmission according to the present invention, and is an example in which the roll of the power unit is detected electromagnetically. In addition,
In this embodiment as well, the same components as in the first embodiment are denoted by the same reference numerals, and the explanation thereof will be omitted.

In FIG. 4, a power unit 80 is formed with a protrusion 80a, and a high frequency oscillation type electromagnetic pickup 81 is provided on the vehicle body 42 facing the protrusion 80a. In addition, electromagnetic pick-up 8
The mounting position of the magnetic pole 82 is determined so that the axis of the magnetic pole 82 does not coincide with the convex portion 80a during normal operation (when no roll occurs). That is, when a roll indicating a shift shock at the time of starting occurs in the direction of the arrow shown by the symbol C in FIG. 4, the convex portion 80a approaches the magnetic pole 82. As a result, the inductance component inside the electromagnetic pickup 81 changes, causing the oscillation frequency of the oscillation circuit 83 to change. In the oscillation circuit 83, when this frequency reaches a predetermined frequency, the detection signal is
Pr is generated and output to the control circuit 47.

In this way, in this embodiment as well, the roll can be detected in the same manner as in the first embodiment, and by performing predetermined control based on this, the same effects as in the first embodiment can be obtained.

Note that the present invention is not limited to the displacement detection means shown in each of the above embodiments. In short, any device that can detect the relative displacement between the power unit and the power unit support may be used, and for example, a displacement meter such as a non-contact potentiometer may be used.

(Effects) This invention detects the torque fluctuation of the output shaft, which causes shift shock, as a relative displacement between the power unit and the power unit support, which reduces shift shock and improves driving feeling. can be done.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing the first embodiment of the present invention, FIGS. 2 and 3 are diagrams showing the second embodiment of the invention, FIG. 2 is an overall configuration diagram, and FIG. 4 is a cross-sectional view showing the displacement detection switch, FIG. 4 is an overall configuration diagram showing the third embodiment of the present invention, and FIGS. 5 a and 5 b show the relationship between shift operation and torque to explain the problems of the prior art FIG. 6 is a timing chart for explaining the operation of the present invention; FIG. 7 is a diagram showing the main part of an accumulator showing a conventional hydraulic control device for an automatic transmission; FIG. , 9 is a diagram showing the hydraulic control device of the automatic transmission of the prior application, FIG. 8 is its overall configuration diagram, and FIG. 9 is a graph showing the characteristics of the output shaft torque to explain its operation. . {43...reflector, 44...light emitter, 45...
Light receiver, 46...detection circuit} Displacement detection means, 47
... Control circuit (control means), 48 ... Actuator (control valve), 52 ... Oil path, {62 ... Displacement detection switch, 71, 72 ... Lead wire} Displacement detection means, R ... Resistance, V ...Power source, 80a... Convex portion, {81... Electromagnetic pickup, 83... Oscillation circuit} Displacement detection means.

Claims (1)

[Scope of Claim for Utility Model Registration] A control valve that opens and closes an oil passage for supplying hydraulic pressure to a frictional engagement mechanism that switches a gear shift state to a drain port, and a control valve that operates to open and close an oil passage that supplies hydraulic pressure to a frictional engagement mechanism that changes a speed change state; A hydraulic control device for an automatic transmission, comprising: a control means for outputting a control signal for opening the control valve and temporarily lowering the engagement hydraulic pressure during the engagement process of the friction engagement mechanism; Displacement detection means for detecting relative displacement between the unit supports is provided, a detection signal from the displacement detection means is input to the control means, and the control means detects a predetermined displacement set in advance by the displacement detection means. A hydraulic control device for an automatic transmission, characterized in that the control valve is opened based on the point in time when the control valve is opened.