JPH04126052U - auto tensioner - Google Patents

Abstract

(57) [Summary] [Purpose] To change the tension of the belt 1 according to the operating conditions of the engine that drives the belt 1. [Structure] The outer circumferential edges of the fixed partition walls 16, 16 whose inner circumferential edges are fixed to the outer circumferential surface of the fixed shaft 9 are connected to the swing housing 11.
slidingly contact the inner peripheral surface of the The inner circumferential edges of the swinging partition walls 17, 17 whose outer circumferential edges are fixed to the inner circumferential surface of the swinging housing 11 are brought into sliding contact with the outer circumferential surface of the fixed shaft 9. Both bulkheads 1
Between 6 and 17, pressure spaces 21, 21 on the pressurizing side and pressure spaces 22, 22 on the depressurizing side are alternately formed. The force with which the tension pulley 20 is pressed against the belt 1 is adjusted by changing the fluid pressure sent to both pressure spaces 21 and 22.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The auto tensioner according to this invention can be used for automotive engine timing belts, Or apply appropriate tension to the belt that drives auxiliary equipment such as the alternator and compressor. Use to give.

0002

[Conventional technology]

To drive the engine auxiliary equipment, a drive mechanism using a belt 1 as shown in Figure 5 is used. The camshaft of an OHC type or DOHC type engine is also used as a crank. In order to drive the rotation in synchronization with the timing belt 1a as shown in Fig. 6, A drive mechanism is used.

0003 In these figures 5 and 6, 2 is rotationally driven by the engine crankshaft. 3 is a driven pulley fixed to the end of the auxiliary input shaft or camshaft. 4 is the tension for applying appropriate tension to belt 1 and timing belt 1a. It's a pulley.

0004 This tension pulley 4 is centered around a fixed shaft 5, as shown in an enlarged view in FIG. 7, for example. A part of the swinging member 6 that swings as a It is. The distal end of the arm piece 7 whose base end is fixed to the swinging member 6 is By connecting one end of the tension spring 8, a tension pulley is attached to the swinging member 6. 4 toward belt 1 (Fig. 5) and timing belt 1a (Fig. 6). It provides elasticity in the direction of the belt 1 and timing belt 1a due to temperature changes, etc. Regardless of dimensional changes or vibrations caused by engine operation, this belt 1 and timing The tension of the belt 1a is always kept constant.

[0005]

[Problem that the idea aims to solve]

However, the conventional auto tensioner as mentioned above does not work regardless of the engine operating conditions. First, since a constant tension was always applied to belts 1 and 1a, in some cases Therefore, the tension applied to the belts 1 and 1a becomes inappropriate, and the belt 1 , 1a and the drive pulley 2, causing abnormal noise, or the belt 1, There was a fear that the lifespan of 1a would be reduced.

[0006] For example, when starting the engine or when a misfire occurs, the engine torque is Because of the rapid fluctuations, the above-mentioned slippage occurs, albeit momentarily. slipping like this In order to prevent this, when the engine torque fluctuates, the belts 1 and It is sufficient to temporarily increase the tension of a, but conventional auto tensioners do not It did not have a tension adjustment function.

[0007] The auto tensioner of this invention was devised in view of the above-mentioned circumstances. .

[0008]

[Means to solve the problem]

The auto-tensioner of this invention has a fixed shaft and a structure concentric with the fixed shaft. A cylindrical rocking housing arranged in A plurality of housings are fixed to a surface and each outer peripheral edge is in sliding contact with the inner peripheral surface of the swing housing. fixed partition walls and their respective outer peripheral edges are fixed to the inner peripheral surface of the swing housing, and a plurality of swinging bulkheads each having an inner circumferential edge in sliding contact with the outer circumferential surface of the fixed shaft, and each swinging bulkhead; A pressure fluid supply hand that supplies pressure fluid into the pressure space existing between the a stage, a swinging arm whose base end is fixed to the swinging housing, and a tip of the swinging arm. A pivot shaft parallel to the fixed shaft provided in the section, and a pivot shaft rotatably supported by this pivot shaft. and a tension pulley, the pressure fluid supply means feeding into the pressure space. The tension applied to the belt by the above tension pulley can be adjusted by changing the fluid pressure. It is said that

[0009]

[Effect]

The autotensioner of the present invention configured as described above has a tensioner that is fed into a pressure space. The housing swings around the fixed axis using fluid pressure or the elasticity of a separately provided spring. The tension plate is supported by a pivot at the tip of the swinging arm. The belt is elastically pressed against the belt to apply appropriate tension to the belt.

0010 When it is necessary to change belt tension due to engine torque fluctuations, etc. The controller changes the fluid pressure applied within the pressure space, and the Press the above tension pulley against the belt by changing the force applied to the webbing. change the power of

[0011]

【Example】

1-2 show an embodiment of the invention. 9 is a fixed shaft, and this fixed shaft 9 is It is unrotatably fixed to the front surface of the engine block 10 or the like. Around this fixed shaft 9, A cylindrical swing housing 11 is arranged concentrically with the fixed shaft 9. This oscillation The housing 11 includes a bottomed cylindrical main part 12 and a lid part 1 that closes the opening of the main part 12. It is composed of 3. The fixed shaft 9 can be freely inserted into the center of the lid part 13. A circular hole 14 is formed, and an O-ring 15 is attached to the inner peripheral edge of the circular hole 14. , the portion through which the fixed shaft 9 passes is kept oil-tight (or air-tight; the same applies hereinafter).

0012 Furthermore, fixed partition walls 16 are provided at two positions on the outer peripheral surface of the fixed shaft 9 on opposite sides in the diametrical direction. , 16 are fixed. Then, the outer peripheral edge of each fixed partition wall 16, 16 is They are in oil-tight sliding contact with the inner circumferential surface of the swing housing 11 and the inner surfaces of both ends in the axial direction. It's set. In addition, two positions on the inner peripheral surface of the swing housing 11 on opposite sides in the diametrical direction The outer circumferential edges of the swinging partition walls 17, 17 are fixed. And each swinging bulkhead 17, 17 are connected to the outer peripheral surface of the fixed shaft 9 and the shaft of the swing housing 11, respectively. It is in oil-tight sliding contact with the inner surface of both ends in the direction.

[0013] Further, the base end of the swing arm 18 is fixed to the outer peripheral surface of the swing housing 11. Ru. A pivot shaft 19 parallel to the fixed shaft 9 is provided at the tip of the swinging arm 18. A tension pulley 20 is placed around the pivot shaft 19 via a rolling bearing (not shown). It is rotatably supported. Then, the outer peripheral surface of this tension pulley 20 is applied with tension. is pressed onto the belt 1 to which it is to be applied.

[0014] Further, between each of the swinging partition walls 17, 17 and each fixed partition wall 16, 16, there is a pressure side. Pressure spaces 21, 21 and pressure reduction side pressure spaces 22, 22 are alternately formed. Immediately In other words, when increasing the tension applied to the belt 1, the swing housing 11 is 1, it swings counterclockwise, but at this time, there is a The space existing between the surface and each fixed partition wall 16, 16 is called pressure side pressure space 21, 2. 1, and in this case, the rear surface of each swinging bulkhead 17, 17 in the swinging direction and each fixed partition 1 6 and 16 are defined as decompression side pressure spaces 22 and 22.

[0015] Inside the fixed shaft 9, there is a pressurizing side passage 23 communicating with the pressurizing side pressure spaces 21, 21. , 23 and pressure reduction side passages 24, 24 communicating with the pressure reduction spaces 22, 22. ing. Then, each passage 23, 24 is discharged from a pressure oil pump via a control valve device. Stores pressure fluid such as discharged pressure oil or compressed air discharged from a compressor. It is connected to a pressure fluid supply means such as an accumulator for storage. and controller However, from the pressure fluid supply means to the pressure side, pressure reduction side, and into each pressure space 21, 22. The tension pulley 20 applies the fluid pressure to the belt 1 by changing the fluid pressure to be sent. The tension is adjustable.

[0016] The autotensioner of the present invention configured as described above has pressure spaces 21 and 2 on the pressurizing side. 1, and the fluid pressure sent into the decompression side pressure spaces 22, 22. Due to the difference in The tension is supported by a pivot 19 at the tip of this swinging arm 18, which swings counterclockwise. The pulley 20 is elastically pressed against the belt 1 to apply an appropriate tension to the belt 1. Give.

[0017] When it becomes necessary to change the tension of belt 1 due to engine torque fluctuations, etc. In this case, the controller changes the fluid pressure applied to the pressurizing side, depressurizing side, and each pressure space 21, 22. by changing the pressure difference between both pressure spaces 21 and 22, and by changing the pressure difference between the pressure spaces 21 and 22, By changing the force applied to the swing housing 11, the tension pulley 20 is The force applied to the belt 1 is changed.

[0018] That is, when it is necessary to temporarily increase the tension of the belt 1, such as when starting the engine, In such a case, the pressure difference is increased and the swing housing 1 is moved through the swing partition walls 17, 17. 1, and press the tension pulley 20 against the belt 1. Increase power. On the other hand, as engine operation reaches a steady state, the belt In order to lower the tension of 1, the differential pressure is reduced and the to reduce the force applied to the swing housing 11, and the tension pulley 20 Reduce the force that presses the belt 1 against the belt 1.

[0019] Next, depending on the operating condition of the engine, the pressure side, the pressure reduction side, and each pressure space 21, 22 are A control valve device for changing the fluid pressure applied to the engine will be explained.

[0020] FIG. 3 shows a first example of the control valve device. Engine speed such as tachometer The output signal of the sensor 25 and the output signal of the wheel rotation speed sensor 26 such as an ABS sensor. , the output signal of the temperature sensor 27 that detects the temperature around the belt is transmitted to the CPU unit. is input to the controller 28.

[0021] In the middle of the supply pipe 47 whose one end is connected to the outlet of the pressure oil or compressed air supply source 29 In order from the supply source 29 side, the source pressure to detect the fluid pressure of this supply source 29 part is The sensor 30, the filter 31, the check valve 32, and the command from the controller 28 A pressure control valve 33 that can be switched is provided. And this pressure control valve 33 The other ends of the pipes 34 and 35, one end of which is connected to the port of It communicates with the passage 24.

[0022] The pressure inside each pipe 34, 35 is detected by pressure sensors 36, 37, respectively. A signal representing the detected value of is input to the controller 28. In addition, the above pressure control valve The other end of the return pipe 38, which has one end connected to the remaining port 33, is connected to the supply source 29. (if using hydraulic pressure) or open to atmosphere (if using pneumatic pressure) There is.

[0023] In the case of the control valve device configured as described above, the controller 28 has the above-mentioned sensors 25, Based on the signals from 26 and 27, the energization to the pressure control valve 33 is controlled, and the On the pressure side, the fluid pressure applied to each pressure space 21, 22 is changed and applied to the belt. Adjust tension.

[0024] Next, FIG. 4 shows a second example of the control valve device. In this second example, each Select four pressure regulating valves 39 to 42 with different set pressures and each pressure regulating valve 39 to 42. Selection valves 43, 44 for selecting the maximum working pressure, pressure regulating valve 45 for setting the maximum working pressure, and supply Select which pipes 34 and 35 the pressure fluid discharged from the source 29 is sent to. It has a switching valve 46 for switching.

[0025] In the case of a control valve device configured as described above, a controller (not shown) controls engine operation. The supply of electricity to the selection valves 43, 44 and the switching valve 46 is controlled according to the switching status, etc., and the pressure side, On the pressure reduction side, the fluid pressure applied to each pressure space 21, 22 is changed to apply it to the belt. Adjust the tension in stages.

[0026] The above description is based on the pressure spaces 21, 21 on the pressurizing side and the pressure spaces 22, 22 on the depressurizing side. By applying fluid pressure to both spaces 21 and 22, the tension pulley The force used to press the belt 20 onto the belt 1 is adjusted, but it depends on the fluid pressure and the elasticity of the spring. The above pressing force may be adjusted by adjusting.

[0027] For example, a spring with sufficiently large elasticity is provided between the swing arm 18 and the fixed shaft 9. However, if it is necessary to increase the tension of belt 1, such as when starting the engine, use this step. The tension of the belt 1 is lowered so that the elasticity of the belt is directly applied to the tension pulley 20. If it is necessary to reduce the pressure, apply appropriate fluid pressure to the pressure reduction side pressure spaces 22, You can also do it.

[0028] Additionally, a tension pulley 20 is separated from the belt 1 between the swinging arm 18 and the fixed shaft 9. A spring with elasticity in the direction of If necessary, apply a sufficiently high fluid pressure in the pressurizing side pressure spaces 21, 21. By applying this, a sufficiently high pressing force can be applied to the tension pulley to overcome the elasticity of the spring mentioned above. If it is necessary to lower the tension of the belt 1, the above-mentioned It is also possible to lower the fluid pressure applied to the pressure side pressure spaces 21, 21.

[0029]

[Effect of the idea]

The auto-tensioner of this invention is constructed and operates as described above, so the belt Even if the rotational torque of the engine that drives the This prevents slippage between the belt and the You can definitely prevent this from happening.

[0030] Also, the tension of the belt is constantly controlled while taking into consideration the circumferential speed of the belt, ambient temperature, etc. This makes it possible to continue to apply optimal tension to the belt, making it easier to maintain the belt than before. has a longer lifespan.

[Brief explanation of drawings]

FIG. 1 is a sectional view taken along the line AA in FIG. 2, showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line BB in FIG. 1;

FIG. 3 is a circuit diagram showing a first example of a control valve device.

FIG. 4 is a circuit diagram showing the second example.

FIG. 5 is a front view showing a drive mechanism of an auxiliary device equipped with an auto-tensioner.

FIG. 6 is a front view showing an engine timing belt drive mechanism also equipped with an autotensioner.

[Figure 7] Built into this timing belt drive mechanism,
FIG. 2 is a front view showing an example of a conventional auto tensioner.

[Explanation of sign]

1 belt 1a Timing belt 2 Drive pulley 3 Driven pulley 4 Tension pulley 5 Fixed axis 6 Swinging member 7 arm piece 8 Tension spring 9 Fixed axis 10 Engine block 11 Swing housing 12 Main part 13 Lid part 14 Round hole 15 O-ring 16 Fixed bulkhead 17 Swing bulkhead 18 Swing arm 19 Axis 20 Tension pulley 21 Pressure side pressure space 22 Decompression side pressure space 23 Pressure side passage 24 Decompression side passage 25 Engine speed sensor 26 Wheel rotation speed sensor 27 Temperature sensor 28 Controller 29 Source of supply 30 Original pressure sensor 31 Filter 32 Check valve 33 Pressure control valve 34 tube 35 tube 36 Pressure sensor 37 Pressure sensor 38 Return pipe 39 Pressure regulating valve 40 Pressure regulating valve 41 Pressure regulating valve 42 Pressure regulating valve 43 Selection valve 44 Selection valve 45 Pressure regulating valve 46 Switching valve 47 Supply pipe

Claims (1)

[Scope of utility model registration request] Claim 1: a fixed shaft; a cylindrical swing housing disposed around the fixed shaft concentrically with the fixed shaft; the inner peripheral edge of each housing being fixed to the outer peripheral surface of the fixed shaft; a plurality of fixed partition walls whose peripheral edges are in sliding contact with the inner circumferential surface of the swing housing; their respective outer circumferential edges are fixed to the inner circumferential surface of the swing housing; and their respective inner circumferential edges are connected to the outer circumferential surface of the fixed shaft; a plurality of swinging bulkheads in sliding contact; a pressurized fluid supply means for supplying pressure fluid into a pressure space existing between each swinging partition and each fixed partition; The pressure fluid supply means has a fixed swinging arm, a pivot provided at the tip of the swinging arm and parallel to the fixed shaft, and a tension pulley rotatably supported by the pivot. The auto tensioner is capable of adjusting the tension applied to the belt by the tension pulley by changing the pressure of the fluid sent into the pressure space.