JPS601446A - Controller for automatic speed change gear - Google Patents

Abstract

PURPOSE:To improve drive feeling by installing a down-shift holding means which holds the operation state of a solenoid during the time when a car speed and the opening degree of a throttle fulfill the respective conditions after the solenoid is put into the operation state on the increased speed change ratio side. CONSTITUTION:A down-shift holding means which holds the operation state of a solenoid during the time when a car speed and the opening degree of a throttle fulfill the respective conditions after the solenoid is put into the operation state on the increased speed change ratio side is installed onto a controller for an automatic speed change gear. Therefore, after down-shift is executed by using a brake, said down-shift state is maintained under a prescribed operation condition, even if the operation of the brake is released. Thus, smooth acceleration can be realized again, and the drive feeling is improved.

Description

[Detailed description of the invention] (b) Technical scope The present invention relates to a control device for an automatic transmission.

(B) Prior art In the case of a vehicle equipped with a normal automatic transmission, if you go down a slope while holding the select lever in the range, the automatic transmission will shift to the highest gear (the gear with the smallest gear ratio). The effect of engine braking becomes very small. For this reason,
In order to obtain the full effect of engine braking, it is necessary to select the 1 select lever to the low gear side. In order to solve the above problems, Japanese Patent Application Laid-Open No. 56-393
No. 49 and JP-A-56-46150. There is a device that forcibly downshifts at the same time as the foot brake is operated, as described in No. This device is provided with a solenoid for switching the valve to the downshift side, and this solenoid is activated when the brake pedal is depressed within a predetermined vehicle speed range. However, in such conventional devices, the solenoid is turned off immediately when the brake pedal is released, and the downshift state is canceled. For this reason, if the driver steps down a slope with the brake depressed and then moves his/her foot from the brake pedal to the accelerator pedal with the intention of accelerating when the road becomes flat, the driver will immediately be in the highest gear. The problem was that the driving force decreased and the driving feeling when reaccelerating was poor. Furthermore, even when the brakes are stopped midway down a slope, the highest speed is immediately reached, reducing the engine braking effect, resulting in an unfavorable driving feeling.

(C) Purpose of the Invention The present invention provides an automatic system that provides a favorable driving feeling and maintains the downshift state until the vehicle speed increases or the throttle opening decreases after the downshift is performed in conjunction with the operation of the brake. The purpose is to obtain a control device for a transmission.

(iv) Structure of the Invention The present invention achieves the above object by providing a downshift holding means that continues the town shift state after the downshift as long as the vehicle speed and throttle opening are within predetermined conditions. That is, according to the present invention, as shown in FIG. 8, a vehicle speed sensor that detects vehicle speed as an electrical signal;
Throttle 7 + - Throttle opening sensor that detects the throttle opening as an electrical signal, brake switch that detects brake operation, and valves of the hydraulic control device to switch between the small gear ratio and the large gear ratio. Based on signals from a solenoid that can control gear changes, a vehicle speed sensor, a throttle opening sensor, and a brake switch, the vehicle speed is within a predetermined range, the throttle is fully closed, and the brake is applied. A control device for an automatic transmission having a downshift control means that outputs a signal for operating the solenoid toward the larger gear ratio side when the solenoid is activated, once the solenoid is in the operating state for the higher gear ratio side. A downshift holding means is provided for maintaining the operating state of the solenoid while the vehicle speed and throttle opening satisfy predetermined conditions.

(D) Examples Examples of the present invention will now be described with reference to FIGS. 1 to 7 of the accompanying drawings.

FIG. 1 shows a skeleton diagram of a transmission mechanism of an automatic transmission with an overdrive gear unit and an overdrive shaft controlled by a control device according to the present invention. This transmission mechanism section includes an l/lux converter section 1, an au/he drive gear unit 2, and 3.
It is composed of a speed gear train section 3. [・Lock-up mechanism of the torque converter unit 1]・The torque converter 4 is configured such that torque from an engine (not shown) is manually applied from the rotating shaft 4a, and the torque is output to the overdrive gear unit 2 via the rotating shaft 4b. It's Nishide. The lock-up clutch 4 is a torque converter with a lock amplifier mechanism.
C, thereby making it possible to mechanically connect the rotating shafts 4a and 4b. The overdrive gear unit 2 has a planetary gear set 5, a direct clutch 6, and an overdrive brake 7. The carrier 5a of the planetary gear set 5 is connected to the torque converter 4 with a lock-up mechanism via a rotating shaft +4b,
Further, the internal gear 5b is connected to the third speed gear train section 3 by a rotating shaft 8. Sun gear 5C and internal gear 5b can be connected by direct clutch 6, and sun gear 5C can be fixed to a stationary part by overdrive brake 7. When the direct clutch 6 is activated and the overdrive brake 7 is deactivated, the carrier 5a, internal gear 5b, and sun gear 5C, which are the components of the planetary gear set 5, rotate together, and the rotating shaft 4b and the rotating shaft 8 is in a connected state (that is, the gear ratio is 1). Conversely, when the direct clutch 6 is deactivated and the overdrive brake 7 is activated, the rotational speed of the internal gear 5b becomes faster than that of the carrier 5a, and the rotation of the rotating shaft 8 is accelerated more than the rotation of the rotating shaft 4b. (that is, the gear ratio is smaller than l and becomes an overdrive state). The 3-speed gear train section 3 is a well-known Simpson type gear train with 3 forward speeds and 1 reverse speed, and includes two planetary gear sets 9 and 1O, two clutches 11 and 12, two brakes 13 and 14, and a one-way clutch 15. It has the brake 13 mentioned above.
, 14.15 and clutches 11.12 are operated in appropriate combinations to realize three forward speeds and one reverse speed.

2 and 3 show the entire control device to which the present invention is applied. This control device includes an oil pump 50° pressure regulator valve 51. Manual valve 52. 1-2 shift valve 53. 2-3 shift valve 54. Pressure modifier valve 55, /<cum throttle valve 56. Throttle backup valve 57. Solenoid downshift valve 58. Second lock valve 59.2-3 timing valve 60. Governor valve 6
1. It has an overdrive release valve 100, a 3-4 shift valve 120, a lock-up control valve 140, etc., but the structure and operation of these are disclosed in, for example, Japanese Patent Application No. 57-079155. Since it is similar, the overdrive release valve 100 will be described below.
I will only briefly explain.

The overdrive release valve 100 switches in response to the on/off state of the overdrive release solenoid 114.
~4 Regardless of the state of the shift valve 120, the overdrive gear unit 2 can be brought into a directly connected state. That is, when the overdrive release solenoid 114 is off, the orifice 112 is open, so no hydraulic pressure acts on the port 1.2a, and the overdrive release valve 100 is shown in the upper half of FIG. in position. In this state, the oil passage 11B and the oil passage 118 are in communication, and the direct clutch 6 and servo release chamber S/R are connected to the oil passage 11B and the oil passage 118.
Hydraulic pressure is supplied in response to switching of the shift valve 120. On the other hand, when the overdrive release solenoid 114 is turned on, the overdrive release valve 100 is switched to the lower half position and the line pressure of the oil passage 108 is supplied to the oil passage 118, so the direct clutch 6 is engaged and the overdrive is activated. The brake 7 is released and the overdrive gear unit 2 is always in a directly connected state. That is, when the overdrive release solenoid 114 is turned on, the fourth speed is switched to the third speed. Overdrive release solenoid 114
is activated by a signal from control device 300.

FIG. 4 shows a block diagram of a control device 300 that controls the operation of the overdrive release solenoid 114. Control device 300 configured by a microcomputer
Signals from four vehicle speed switches S1, S2, S3, and S4, a signal from brake switch B, and a signal from throttle opening sensor TH are input to . Based on these input signals, control device 300 outputs a signal that controls the operation of overdrive release solenoid 114 as described later. The vehicle speed switches S1 to S4 are turned on in the vehicle speed range shown in FIG. That is, the vehicle speed switch S1 is turned on at a vehicle speed of 25 to 7'O'km/h, and the vehicle speed switch S is turned on at a vehicle speed of 25 to 40 km/h.
The vehicle speed switch S3 is turned on when the vehicle speed is 40 to 5.
It turns on at 5 km/h, and the vehicle speed switch S4
is turned on at vehicle speeds of 55 to 70 km/'h. The throttle opening sensor TH outputs a voltage signal that increases according to the throttle opening. Brake switch B is turned on when pedal force is applied to the brake pedal. FIG. 6 shows the control □ performed by the control device 300 as a flowchart. First, it is determined whether the vehicle speed switch S1 is on (step 204). If the vehicle speed switch S1 is off, the vehicle is not at a speed at which the overdrive state should be released, so the overdrive release solenoid 114 is turned off, step 206), and the process returns. If the vehicle speed switch S is on, it is determined whether the overdrive release solenoid 11.4 is on (step 208); if it is off, it is determined whether the throttle opening is 0, that is, fully closed. to judge (
Step 210). If the throttle opening is not O in step 210, the process returns directly; if the throttle opening is 0, it is determined whether the brake switch B is on (step 212); if the brake switch B is off, the process continues as is. If the brake switch B is on, the overdrive release solenoid 114 is turned on (step 214), and the process returns.

That is, when the vehicle speed switch Sl is in a predetermined speed range (25 to 70 km/h) where it is turned on, the throttle is fully closed, and the brake is activated, the overdrive release solenoid 114 is turned on. Set to 3rd gear. If the overdrive release solenoid 114 is on in step 208, it is determined whether the brake switch B is on or not (step 216).
, if it is on, it returns as is, and if it is off, it is determined whether the vehicle speed switch S2 is on or off (step 2
18). When the vehicle speed switch S is on, the throttle and torque setting values THD should be set to D].
Proceed to step 222. Note that the value will be explained later along with DZ and D3, which will be described later. If the vehicle speed switch Sz is off in step 218, it is determined whether the vehicle speed switch S3 is on (step 224). When the vehicle speed switch S3 is on, the throttle setting value TH
Set Dz as D (Step 226), Step 2
Proceed to 22. In addition, if the vehicle speed switch S4 is off, step 2 determines whether the vehicle speed switch S4 is on or off.
28) If the vehicle speed switch S4 is on, the throttle setting value THD is set and D3 is set. Step 230) and the process proceeds to step 222. In step 222, it is determined whether the signal THR from the throttle opening sensor corresponding to the actual throttle opening is larger than the throttle setting value THD. If THR is greater than THD,
As is (i.e. overdrive release solenoid 1
14 remains on) Return. If THR is smaller than THD, overdrive release solenoid 114
is turned off and the process returns to step 232). The values D1, DZ, and D3 of the throttle setting value THD described above are set to increase in the order of Dl, DZ, and 03, as shown in FIG. 7.In the end, the control from step 218 to step 232 The following control is executed. That is, when the vehicle speed and throttle opening are in the region to the left of the stepped shift line shown in FIG. 7, the overdrive release solenoid 114 remains on.
In the region to the right of the shift line, the overdrive release solenoid 114 is turned off. This stepped shift line is set in a region to the right of the normal 3-4 upshift shift line obtained by the 3-4 shift valve 120 (that is, in a region where the vehicle speed is higher). Therefore, when the vehicle goes down a slope, the following control is obtained. When the vehicle approaches a downhill road at a speed of 25 to 70 km/h and the driver switches from the accelerator pedal to the brake pedal, the overdrive release solenoid 114 is activated under the control of step 204 → step 208 → step 210 → step 212 → step 214. is turned on, and the automatic transmission switches from the fourth gear to the third gear. Once the overdrive release solenoid 114 is turned on, the process proceeds from step 208 to step 216, but as long as the brake is continued to be depressed, the overdrive release solenoid 114 will remain on. When the brake switch is released, the process advances to step 218, but under the control from step 218 to step 232, the overdrive release solenoid 114 is turned on in the operating state on the left side of the stepped shift line shown in FIG. Retained. Therefore, even if the driver switches from the brake pedal to the accelerator pedal halfway down a slope or at the end of the slope, if the driving state is in the area to the left of the shift line shown in state is maintained. The overdrive release solenoid 114 turns off and enters the 4th speed state when the operating state reaches the region to the right of the shift line shown in FIG. 7, that is, when the throttle opening is reduced. This is the case when the vehicle speed increases. in the end,
When switching from the brake pedal to the accelerator pedal,
Since the third gear state is maintained until the predetermined driving conditions are reached, acceleration when re-accelerating after completing a downhill slope is improved.
Further, it is possible to prevent the problem of shifting from third gear to fourth gear against the driver's intention during a downhill slope.

In the above embodiment, four vehicle speed switches are used, but by using more vehicle speed switches or by using a vehicle speed sensor that can continuously detect vehicle speed, the stepped shape shown in FIG. The shift line can also be made into a finer step-like shape or a smooth curve.

(f) As described in detail, the present invention includes a vehicle speed sensor that detects vehicle speed as an electrical signal, a throttle opening sensor that detects throttle opening as an electrical signal, and a sensor that detects brake operation. A brake switch and a solenoid (in the embodiment, the overdrive release solenoid 114) capable of controlling the shift between a gear position on the small side of the gear ratio and a gear position on the large side of the gear ratio by switching the pulp of the hydraulic control device.

Based on signals from the vehicle speed sensor, throttle opening sensor, and brake switch, the solenoid is operated to the larger gear ratio side when the vehicle speed is within a predetermined range, the throttle is fully closed, and the brake is operating. In an automatic transmission control device having a downshift control means that outputs a signal, once the solenoid is in the operating state on the large gear ratio side, as long as the vehicle speed and throttle opening satisfy predetermined conditions, A downshift holding means is provided to maintain the operating state of the solenoid.
After using the brakes to downshift, the downshift will be maintained under certain driving conditions even if the brakes are released, allowing for smooth re-acceleration and improved driving feeling. do.

[Brief explanation of the drawing]

Figure 1 is a skeleton diagram of the automatic transmission, Figures 2 and 3 are lock diagrams, Figure 5 is a diagram showing the five operating ranges of the vehicle speed switch, Figure 6 is a diagram showing a control flowchart, and Figure 7 is a shift line. 8 are diagrams showing the relationship between the configurations of the present invention. Patent applicant agent Patent attorney Toshiyuki Miyauchi Figure 4 Figure 5 z! :+4UbblUkrY1/1. l mouth

Claims (1)

[Claims] 1. A vehicle speed sensor that detects vehicle speed as an electrical signal, a throttle opening sensor that detects throttle opening as an electrical signal, a brake switch that detects brake operation, and a valve of a hydraulic control device. The vehicle speed is controlled to a predetermined level based on signals from the vehicle speed sensor, throttle opening sensor, and brake switch. A control device for an automatic transmission, comprising a downshift I/control means for outputting a signal to operate the solenoid to a larger gear ratio side when the throttle is within the range, the throttle is fully closed, and the brake is operating. The downshift holding means maintains the solenoid in the operating state as long as the vehicle speed and the throttle opening satisfy predetermined conditions, once the solenoid is in the operating state on the larger gear ratio side. automatic transmission control device. 2. The predetermined condition for vehicle speed and throttle opening is that the actual throttle opening is larger than the predetermined throttle opening, which increases in accordance with the vehicle speed. A control device for the automatic transmission described above.