JPH0453484Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention relates to automatic transmissions, and in particular calculates the appropriate gear position and automatically adjusts the gear position to the value obtained by this calculation. The present invention relates to an automatic transmission in which the gear position is changed by an actuator.

〓Summary of the invention〓 This invention repeatedly engages and disengages the hydraulic clutch attached to the automatic transmission when the oil temperature of the hydraulic clutch is below a predetermined value and the transmission is in neutral. This facilitates warm-up of the hydraulic clutch at low temperatures, and enables smooth control of engagement and disengagement of the clutch at a predetermined oil temperature.

<Prior Art> Automatic transmissions have been proposed to omit the driver's complicated gear shifting operations. In this automatic transmission, a calculation means such as a microcomputer selects the gear to be used depending on the vehicle speed, accelerator opening, etc., and the gear selected by the actuator is engaged to automatically set a predetermined gear ratio. It was designed to obtain By equipping an automobile with such an automatic transmission, the driver hardly needs to operate a lever to change gears.

Problems to be Solved by the Invention In such automatic transmissions, the clutch is engaged by pressing the accelerator pedal. Furthermore, when the vehicle speed is reduced and the engine speed falls below a predetermined speed, the clutch is automatically disengaged, thereby preventing the engine from stalling. Therefore, when the vehicle is stationary and the transmission is in neutral, the clutch is in principle in a disconnected state and stops rotating. Therefore, even if the engine is warmed up at a low temperature, the clutch oil temperature will not rise and the clutch will not be warmed up. When a hydraulic clutch is used as the clutch, there is a problem in that the hydraulic system of the hydraulic clutch is not warmed up at low temperatures.

The present invention was devised in view of these problems, and the object is to provide an automatic transmission that can warm up a hydraulic clutch at low temperatures without using a special warm-up device. That is.

〓Means for solving the problem〓 As shown in Fig. 1, the present invention calculates the appropriate gear position and automatically controls the actuator to reach the value obtained by this calculation. A transmission that changes the gear position by moving the transmission, comprising: a hydraulic clutch interposed between the transmission and the engine; a switching means for switching between engagement and disengagement of the hydraulic clutch; The automatic transmission is characterized by comprising: a detection means for detecting the clutch; and a means for repeating the engagement and disengagement of the hydraulic clutch when the oil temperature of the clutch is below a predetermined value when the transmission is in a neutral state. It concerns transmission.

〓Effect〓 Therefore, according to the present invention, when the oil temperature of the hydraulic clutch is below a predetermined value in the neutral state, the engagement and disengagement of the hydraulic clutch are automatically repeated, and thereby This makes it possible to accelerate the warm-up of the hydraulic clutch.

〓Example〓 The present invention will be described below with reference to an illustrated example.
FIG. 2 shows an engine for an automobile equipped with an automatic transmission according to an embodiment of the present invention, and this engine is composed of a diesel engine 10 for a truck. The diesel engine 10 is equipped with a fuel injection pump 11, which sequentially supplies fuel to each cylinder of the engine 10.
The fuel injection pump 11 is driven by the engine 10 via a timer 12, and the timing of fuel injection is adjusted by the timer 12. Furthermore, the fuel injection pump 11 is equipped with a governor 13, and this governor 1
3 to adjust the fuel injection amount.

A flywheel housing 14 is provided on the rear side of the engine 10, and this housing 1
A flywheel fixed to the end of the crankshaft is housed within the crankshaft. A hydraulic clutch 30 is provided on the back side of this flywheel, and this clutch 3
A transmission 15 is attached to the rear side of the flywheel housing 14 so as to be connected to the flywheel housing 14. This transmission 15 is
The rotational speed of the engine 10 is changed to a predetermined value and transmitted to the drive wheels via the propeller shaft 16.

The transmission 15 constitutes an automatic transmission, and a shift actuator 17 and a selection actuator 18 are provided above the transmission. Furthermore, clutch 3 is attached to the back side of the flywheel.
A hydraulic actuator 19 is mounted on the flywheel within the housing 14 for controlling the connection and disconnection of the 0. Furthermore, a fuel control actuator 20 is provided at the front end of the fuel injection pump 11 to adjust the position of the control rack and control the amount of fuel supplied. These four actuators 17, 18, 19, 20
are adapted to be driven based on instructions from the microcomputer 21 via respective driving means.

The input side of the microcomputer 21 is connected to a control box 22. This control box 22 is the gear shift lever 2.
It has 3. Furthermore, this microcomputer 21 is connected to an accelerator sensor 25 that detects the opening degree of the accelerator or the amount of depression of the accelerator pedal 24. Further, the microcomputer 21 is connected to a vehicle speed sensor 26, an engine rotation sensor 27, a rack sensor 28, a clutch sensor 29, and an oil temperature sensor 31, respectively.

The vehicle speed sensor 26 is provided on the side of the transmission 15.
The vehicle speed is detected based on the rotational speed on the output side of the engine. Further, the engine rotation sensor 27 is attached to the front side of the engine 10 and is adapted to detect the rotation speed of the engine 10. Furthermore, the rack sensor 28 is connected to the actuator 20.
It is attached to the tip side of the fuel injection pump 1.
The position of the control rack No. 1 is detected. Further, the clutch sensor 29 is attached to the distal end side of the clutch actuator 19, and is adapted to detect the connected and disconnected states of the clutch 30. Also, the oil temperature sensor 31
is attached to the oil pan of the clutch 30 and is adapted to detect the oil temperature of the clutch 30.

Next, the structure of the hydraulic clutch 30 will be explained with reference to FIG. is fixed. A ring gear 37 is fixed to the outer peripheral side of the flex plate 36. A flywheel 38 is also fixed to the flex plate 36. The flywheel 38 is provided with the hydraulic cylinder 19, and the piston 4
0 is slidably supported.

The piston 40 includes an arm 41, and
By this arm 41, the pressure plate 42
I try to support. The pressure plate 42 is adapted to press a clutch facing 45 attached to the clutch disk 43 against a pressure receiving surface of the clutch cover 45. Note that the clutch disc 43 is connected to the hub 47 via a buffer spring 46.
is connected to.

An oil pump 49 is provided in a clutch housing 48 fixed to the flywheel housing 14, and this oil pump 49 is driven by a gear 51 fixed to the clutch cover 45 via a drive gear 52 of the pump 49. It is becoming driven. The oil pump 49 is also connected to a strainer 53, and the strainer 53 sucks the oil in the oil pan 54. Furthermore, the oil pump 49 is connected to an oil spray hole 55 and is configured to inject oil onto the clutch facing 44.

A pair of ports 57 and 58 are formed in a retainer 56a and a sleeve 56b, respectively, which are attached to the outer peripheral side of the clutch shaft 50.
These ports 57, 58 are connected to the port 49a of the oil pump 49 via a switching valve (not shown). Furthermore, ports 57 and 58 are connected to pipe 5.
Oil supply holes 61, 6 of the flywheel 38 through the passage 40 inside the pipe 59 and outside the pipe 59.
2 are connected to each other.

Next, the operation of this automatic transmission configured as described above will be explained. This operation is performed based on a program preset in the microcomputer 21.
When the shift lever 23 of the control box 22 is in the automatic position, the shift operation is automatically performed. On the other hand, when the shift lever 23 is in the manual position, the manually selected shift operation is performed by the actuator 1.
7 and 18.

To give an overview of the operation of automatic gear shifting, the microcomputer 21 detects whether the gear shift lever 23 of the control box 22 is in the automatic position, and if it is in the automatic position, the accelerator pedal 24 is depressed at regular intervals. The accelerator sensor 2 detects the amount or accelerator opening degree and vehicle speed.
5 and the vehicle speed sensor 26. Further, the microcomputer 21 reads the map stored in its memory, and based on this map, calculates whether automatic gear shifting is possible. If automatic gear shifting is possible, gear shifting is performed to obtain the calculated gear ratio. On the other hand, if it is determined that automatic gear shifting is not possible, gear shifting is not performed.

The specific operation of automatic gear shifting is such that the shift actuator 17 and the selection actuator 18 are operated based on a command from the microcomputer 21 via a drive means (not shown), and the gears of the transmission 15 are selected. The selected gears of the transmission 15 are thereby brought into mesh. Therefore, a predetermined gear ratio can be obtained in this way. Note that during this gear shifting operation, the clutch 30 is temporarily closed by the hydraulic actuator 19.
The clutch 30 is switched to the disconnected state, and the clutch 30 is brought into the connected state again in synchronization with the end of the gear shifting operation.

Next, the operation of the hydraulic clutch 30 will be explained. The oil pump 49 of the hydraulic clutch 30 sucks the oil accumulated in the oil pan 54 through the strainer 53, pressurizes this oil, and sends it out. The pressurized oil is injected into the clutch facing 44 through the oil spray hole 55, thereby lubricating and cooling the friction parts of the clutch facing 44, thereby preventing half-drivings such as creep running. The clutch is constructed so that it can withstand even if the clutch state continues for a long time.

Furthermore, this oil pump 49 is connected to ports 57 and 58 of a retainer 56a and a sleeve 56b via a switching valve (not shown). When connected to port 57, pipe 5
9 and the hydraulic cylinder 1 through the oil passage 61.
Oil is supplied to the front chamber of 9, thereby pushing the piston 40 rearward. Therefore, the pressure plate 42 presses the clutch facing 44 against the pressure receiving surface of the clutch cover 45, thereby switching the clutch into the connected state.

On the other hand, when the oil pump 49 is communicated with the other port 58 of the sleeve 56b by a switching valve (not shown) that is interlocked with a control device, the oil in the passage 60 outside the pipe 59 and the flywheel 38 is Oil is supplied to the rear chamber of the piston 40 through the supply hole 62. Therefore, in this case, the piston 40 moves forward, and the pressure on the clutch facing 44 by the pressure plate 42 is released. This allows the clutch 30 to be switched to the disengaged state.

The hydraulic clutch 3 attached to the automatic transmission 15 that performs automatic gear shifting in this manner
0 is connected by depressing the accelerator pedal 24, and when the accelerator pedal 24 is depressed at the time of starting the vehicle, the clutch 30 is connected. Furthermore, when the vehicle is decelerated, the rotational speed of the engine 10 decreases accordingly. When the rotational speed of the engine 10 reaches a predetermined rotational speed, the clutch 30 is automatically disconnected by the hydraulic cylinder 19.
This prevents the engine 10 from stalling. Therefore, the hydraulic clutch 30 provided in such a transmission 15
In principle, when the vehicle is stopped or when the transmission 15 is in neutral, the system is shut off for safety even if the control system such as the microcomputer should fail. Therefore, even if the engine 10 is warmed up while stopped in winter, the clutch 30 remains stationary without rotating, and the spray oil, whose oil temperature rises when the clutch is engaged or disengaged, does not warm up when the temperature is low. Not done.

In order to eliminate this inconvenience, the hydraulic clutch 30 according to this embodiment is designed to automatically repeat engagement and disengagement when the oil temperature is below a predetermined value. That is, the microcomputer 21
As shown in Figure 3, the control box 2
2 is read, and it is determined whether the shift lever 23 is in the neutral position. In the case of neutral, the output of the oil temperature sensor 31 of the hydraulic clutch 30 is further read, and it is determined whether this value is greater than or equal to a predetermined value. When the oil temperature is below a predetermined value, the state of the clutch 30 is read by the clutch sensor 29, and when the oil temperature is in the disconnected state, the state of the clutch 30 is read.
and when connected, this clutch 30
will be blocked. Since the program shown in FIG. 3 is repeatedly executed at predetermined time intervals, the clutch is automatically connected and disconnected repeatedly.

As described above, in the transmission 15 according to this embodiment, when the clutch 30 is in the neutral state and the oil temperature of the hydraulic clutch 30 is low, the clutch 30 repeatedly engages and disengages.
That is, the oil sprayed on the clutch disk 43 absorbs the frictional heat generated by the slip between the clutch disk 43 and the pressure plate 42, and the temperature of the oil increases. Therefore, this makes it possible to accelerate the warm-up of not only the engine 10 but also the hydraulic clutch 30 at low temperatures. In addition, the lever 23 of the control box 22
When is in a position other than neutral, normal automatic gear shifting operation is performed. Further, when the oil temperature of the hydraulic clutch 30 is above a predetermined temperature, the clutch 30 is maintained in the disconnected state and does not repeatedly engage and disengage. Also, in this example,
Although the oil temperature of the hydraulic clutch 30 is detected by the oil temperature sensor 31, the oil temperature may also be indirectly detected by other temperature sensors, such as a water temperature sensor of the engine 10. It is possible.

Effects of the Invention As described above, in the present invention, when the oil temperature of the hydraulic clutch is below a predetermined value in the neutral state, the hydraulic clutch is repeatedly engaged and disengaged. Therefore, with this configuration, it is possible to accelerate the warm-up of the hydraulic clutch at low temperatures.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the gist of the invention, Figure 2
The figure is a block diagram showing an automatic transmission according to an embodiment of the present invention, Figure 3 is a flowchart showing the warm-up operation of the hydraulic clutch of this automatic transmission, and Figure 4 is a longitudinal section of the hydraulic clutch. It is a diagram. The names of the main parts in the drawing are as follows.
15... Transmission, 17... Shift actuator, 18... Selection actuator, 19... Hydraulic actuator, 21... Microcomputer, 22... Control box, 23... Gear shift lever, 30... Hydraulic clutch , 31...Oil temperature sensor.

Claims (1)

[Scope of Claim for Utility Model Registration] In a transmission that calculates an appropriate gear position and automatically changes the gear position using an actuator so as to reach the value obtained by this calculation, a hydraulic clutch interposed between the transmission and the engine; a switching means for switching engagement and disengagement of the hydraulic clutch; a detection means for detecting oil temperature of the hydraulic clutch; and a state in which the transmission is in neutral. An automatic transmission comprising: means for repeatedly engaging and disengaging the hydraulic clutch when the oil temperature of the clutch is below a predetermined value.