KR19980068093U - Multi-plate Clutch for Automatic Transmission - Google Patents

Abstract

An object of the present invention is to provide a multi-plate clutch for an automatic transmission configured to prevent the surface of the clutch plate from being damaged by foreign matter interposed between the clutch plates. The multi-plate clutch of the present invention is used to connect the operating elements of the planetary gear device to each other in accordance with the supply of hydraulic pressure and to rotate them integrally or to block the connection of the operating elements. A plurality of clutch discs having a plurality of radial grooves and axially movable on the second actuating element, alternately arranged between the clutch discs, and axially moved by hydraulic pressure to make frictional contact with the clutch discs. It consists of a plurality of clutch plates.

Description

Multi-plate Clutch for Automatic Transmission

The present invention relates to a multi-plate clutch of an automatic transmission for a vehicle, and more particularly, to a multi-plate clutch for an automatic transmission configured to prevent the surface of the clutch plate from being damaged by foreign matter interposed between the clutch plates.

A vehicle transmission is a device used to change the rotational force and rotational speed of the engine to the driving situation and transmit it to the driving wheel or to reverse the driving wheel, and is divided into a manual transmission, an automatic transmission, and a continuously variable transmission.

The manual transmission is configured to change the bite of the gear by transmitting the operating force directly to the gear in the transmission housing as the driver operates the shift lever, and generally moves forward according to the bite state of the gears arranged on the main shaft and the minor shaft. A gear ratio of five gears and 1-2 reverse gears can be achieved. In such a manual transmission, since the rotational force of the engine must be shut off before shifting by operating the shift lever, the use of a clutch device is essential.

On the other hand, an automatic transmission automatically performs a clutch action and a shifting action, and a combination of a torque converter and a planetary gear device is widely used. The torque converter ensures that the rotational force of the engine is transmitted to the input shaft of the planetary gear unit when the engine is idle, and increases the torque transmitted to the input shaft of the planetary gear unit as the engine rotation speed increases. Rotational rotation of the engine causes fluidic connection between the input shafts of the engine and the planetary gear system so that they both rotate at about the same speed. Recently, when the rotational speed of the engine is higher than a certain speed, a lockup device that maximizes the power transmission efficiency of the torque converter by mechanically connecting the input shaft of the engine and the planetary gear device is used. However, the torque converter has a limit to increase the torque of the engine to a desired value and cannot change the direction of rotation. Therefore, the planetary gear system must be used to shift the vehicle to the actual driving conditions.

The planetary gear device of the automatic transmission basically consists of a sun gear, a ring gear and a pinion gear disposed between them to rotate or revolve, and each pinion gear is connected to each other by a pinion carrier. The speed ratio depends on which sun gear, ring gear and pinion carrier are fixed and which are input or output. For example, when the sun gear is input and the pinion carrier is output while the ring gear is fixed, deceleration is performed at a specific reduction ratio. Similarly, when the pinion carrier is input and the sun gear is output while the ring gear is fixed, speed is increased at a specific speed ratio. On the other hand, when the pinion carrier is fixed and the sun gear is input and the ring gear is output, the rotation directions of the input shaft and the output shaft are reversed, and the vehicle can be reversed. If two of the gears of the planetary gear are input at the same time, all the gears rotate together and the transmission ratio becomes 1. Examples of such a planetary gear device include a simple planetary gear device, a Simpson type planetary gear device, a Lavigno type planetary gear device, and the like, and as the structure of the planetary gear device becomes more complicated, various gear ratios can be obtained.

In the planetary gear device, the movement of the sun gear, the ring gear or the pinion carrier is regulated by a multi-plate clutch, a one-way clutch, a band brake, or the like provided correspondingly. The multi-plate clutch and the band brake are hydraulically operated, and the hydraulic pressure is appropriately controlled by the hydraulic controller. The hydraulic control device of the automatic transmission consists of an oil pump for generating oil pressure, a valve body having a flow path configured to distribute oil pressure to each part, and various valves installed in the valve body. Examples of valves used in hydraulic control systems include manual valves, pressure regulating valves, governor valves, throttle valves, 1-2 speed shift valves, 2-3 speed shift valves, 3-4 speed shift valves, and reverse valves. have. The manual valve determines shift ranges such as parking (P), reverse (R), neutral (N), drive (D), and low speed (2, 1) according to the operation of the shift lever. The governor valve and the throttle valve control the positions of the various shift valves according to the vehicle speed and the throttle opening, respectively, so that the automatic shift is performed at a desired speed ratio in the drive range.

In the automatic transmission, which has been put to practical use in recent years, an electronic control unit (TCM) detects the driving state of a vehicle, in particular, the vehicle speed and the throttle opening, and controls the valve operation of the hydraulic control unit, thereby supplying it to the clutch and brake of the planetary gear unit. The optimum shift is performed by controlling the oil pressure. The types of shifts that are co-operated by the electronic control unit and the hydraulic control unit include upshifts that shift from low speed to high speed, downshifts that shift from high speed to low speed, and kickdowns performed when the accelerator pedal is pressed rapidly during high speed driving. There are shifts and skip shifts for shifting by skipping two or more steps at once.

As shown in Figure 1, a conventional automatic transmission is a torque converter (10) operatively connected to the engine to the torque multiplication action and the fluid clutch action, and the transmission housing to change the rotational speed and rotational direction of the transmission input shaft ( 12 is provided with a planetary gear device 14 provided therein, and a differential gear device 16 is disposed at an output end of the planetary gear device 14. The operation of the planetary gear device 14 is regulated by the band brake 18, the multi-plate clutch 20, the multi-plate brake 22, and these brakes and the clutch are operated by hydraulic pressure.

2 shows an enlarged cross-sectional view of a multi-plate clutch 20 employed in a conventional automatic transmission. The multi-plate clutch 20 is arranged in an axial direction with a plurality of clutch discs 26 provided at intervals on the first actuating element 24 of the planetary gear device and the second actuating element 28 of the planetary gear device. It is composed of a plurality of clutch plates 30 which are slidably installed and are alternately arranged between the clutch discs 26. As the clutch piston 30 is extended by hydraulic pressure, the clutch disc 26 and the clutch plate 30 come into frictional contact with each other, whereby the first actuating element 24 and the second actuating element 28 are in contact with each other. ) Rotates integrally. In contrast, when the clutch piston 32 is retracted, the clutch plate 30 is disengaged from the clutch disc 26 and the first actuating element 24 and the second actuating element 28 move separately from each other.

However, in the conventional multi-plate clutch 20, when foreign matter such as metal particles is interposed between the clutch disk 26 and the clutch plate 30, the clutch disk 26 or the clutch plate ( In addition to the damage to the surface of 30), the frictional force is lowered, which may cause power transmission uncertainty. Replacing a damaged clutch disc 26 or clutch plate 30 requires a lot of time, money, and effort, and measures are required to prevent such damage in advance.

The present invention has been made to solve the problems of the prior art as described above, the purpose of which is an automatic transmission that can prevent the surface of the parts damaged or deteriorated power transmission efficiency by foreign matter interposed between the friction contact surface. It is to provide a multi-plate clutch for.

The above object of the present invention is a multi-plate clutch which is used to connect the first and second operating elements to each other to rotate integrally or to block the connection of both, and is provided at intervals on the first operating elements. A plurality of clutch discs and a plurality of clutch plates slidably axially mounted to the second actuating element and alternately arranged between the clutch discs, the clutch discs facing the clutch plate; A multi-plate clutch for an automatic transmission is characterized by having a plurality of radial grooves formed in the viewing surface.

1 is a cross-sectional view of a conventional automatic transmission employing a multi-plate clutch.

2 is a cross-sectional view of a conventional multi-plate clutch.

3 is a cross-sectional view of the multi-plate clutch according to the present invention.

4 is a front view of the clutch disk of the multi-plate clutch according to the present invention.

5 is an explanatory view showing the principle that foreign matter is collected in the radial groove of the clutch disk.

♣ Explanation of symbols for the main parts of the drawing ♣

100: first operating element 102: clutch disc

104: second actuating element 106: clutch plate

108: clutch piston

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 3 to 5 of the accompanying drawings.

3 and 4, it can be seen that the multi-plate clutch for the automatic transmission of the present invention includes a plurality of clutch discs 102 which are installed at intervals on the first operating element 100 of the planetary gear device. have. The inner peripheral surface of the first actuating element 100 is provided with a plurality of key grooves 100a in the axial direction, and the root portions of the clutch disc 102 are coupled to these key grooves 100a. Therefore, the clutch disc 102 can slide in the axial direction with respect to the first actuating element 100 but not in the circumferential direction.

A plurality of clutch plates 106 are provided at intervals on the second actuating element 104 of the planetary gear device. These clutch plates 106 are alternately arranged between the clutch discs 102 and are in selective frictional contact with the clutch discs 102. A plurality of key grooves 104a are provided on the outer circumferential surface of the second operating element 104 in the axial direction, and the root portions of the clutch plate 106 are coupled to the key grooves 104a. Thus, the clutch plate 106 can slide in the axial direction with respect to the second actuating element 104 but not in the circumferential direction.

The clutch disk 102 and the clutch plate 106 are axially moved by the clutch piston 108 to be in frictional contact. In other words, when the clutch piston 108 is advanced in the direction of the arrow of FIG. 3 by the hydraulic pressure supplied from the hydraulic control device of the automatic transmission, the clutch disc 102 and the clutch plate 106 are brought into frictional contact with each other. The first actuating element 100 and the second actuating element 104 are connected to each other and rotate integrally. Conversely, when the clutch piston 108 retracts, the frictional contact between the clutch disc 102 and the clutch plate 106 is released, and the first actuating element 100 and the second actuating element 104 are independent of each other. It becomes movable.

On the other hand, each clutch disk 102 has a plurality of radial grooves 102a arranged at equal intervals on the surface facing the clutch plate 106. This radial groove (102a) is to damage the surface of the clutch disk 102 or clutch plate 106 by trapping foreign matter interposed between both when the clutch disk 102 and the clutch plate 106 is in frictional contact. Prevent and reduce friction. As shown in FIG. 5, since the clutch disk 102 and the clutch plate 106 make relative rotational movements just before the friction contact, foreign matter interposed between them in this process is the radial groove of the clutch disk 102. (102a) Swept into

As described in detail above, according to the multi-plate clutch of the present invention, foreign matter interposed between the clutch disk and the clutch plate can be collected in a radial groove formed in the clutch disk, thereby preventing damage to the friction surface and The outstanding effect that the improvement of frictional force can be aimed at is acquired.

Claims (1)

A multi-plate clutch used to connect the first and second actuating elements to each other to rotate integrally or to block the connection of both of the first and second actuating elements, comprising: a plurality of clutch discs spaced apart from the first actuating element; A plurality of clutch plates axially slidably installed in the actuating element of 2 and alternately arranged between the clutch discs, the clutch discs having a plurality of radial grooves formed on a surface facing the clutch plate; Multi-plate clutch for automatic transmission characterized in that it comprises a.