JPH08232838A - Power interruption mechanism in compressor - Google Patents

Abstract

PURPOSE: To obtain a power interruption mechanism in a compressor which can properly interrupt an overload torque on the side of a compressor. CONSTITUTION: A driving force receiving body 8 fixed to a rotary shaft is connected to a connection base plate 6-1 on the side of a pulley 6 rotatably supported to a housing by means of two breakable pins 10 in a power transmitting manner. Belleville springs 12-1, 12-2 are arranged between the head of each breakable pin 10 and a stepped portion 6-5 inside a through-hole 6-3 formed on the connection base plate 6-1. One belleville spring 12-1 is smaller than the other belleville spring 12-2. When the pulley 6 is rotated in such a state that an overload is applied to a compressor and a rotary shaft and the driving force receiving body 8 are locked, breakable portions 10-3 of the breakable pins 10 are broken, and breakable portions 11-3 of breakable pins 11 are broken.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power cutoff mechanism in a compressor for transmitting a driving force of an external drive source to a rotary shaft via a pulley.

[0002]

2. Description of the Related Art In a clutchless compressor, a pulley which is rotated by a driving force of an external drive source is mounted on a housing, and power is coupled between a protruding end of a rotary shaft supported by the housing and the pulley. The electromagnetic clutch that repeatedly shuts off is not used. This compressor can eliminate the deterioration of the sensible feeling due to the ON / OFF shock particularly in the vehicle-mounted form. Further, it is possible to reduce the weight and cost of the entire compressor. However, in such a clutchless compressor, the fluctuation of the load torque on the compressor side is not alleviated and spreads to the vehicle engine, so that the rotation speed of the vehicle engine fluctuates.

In the clutchless compressor disclosed in Japanese Utility Model Laid-Open No. Sho 63-19083, a pulley and a rotary shaft are connected by an overload breakable material (pin). That is, a pair of overload rupturable pins are erected on a driving force receiving body fitted and fixed to the rotating shaft, and both pins are engaged with holes formed in the side wall of the pulley. When the load torque on the compressor side becomes excessive, both of the pins are broken at the same time, and the pulley idles so that the excessive load torque does not spread to the vehicle engine side.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the configuration of the overload breakable pin disclosed in Japanese Patent No. 19083, it is difficult to achieve both the breaking torque and the fatigue strength of the overload breakable pin. That is, even if the breaking torque when the breaking pin breaks due to overload is set properly, overloading is possible due to the repeated action of fluctuating load torque during normal operation that is less than the set breaking torque. The breaking pin may be fatigued, and the overloadable breaking pin may be broken by a load torque equal to or lower than the breaking torque. In particular, when the compressor is turned on / off, the starting / breaking torque is transmitted from the pulley directly to the overload rupturable pin by shock, so fatigue progression of the pin is unavoidable.

Further, since both of the breakable pins are configured to be broken at the same time, it is necessary to reduce the breaking strength of a single pin to half, which easily causes the fatigue of the overload breakable pin described above. Also from the point of view, there is an increased possibility that the breakable pin will be broken by a load torque equal to or lower than the breaking torque.

A plurality of breakable pins are usually used, but there is also a case where there is only one. In this case, it is not necessary to reduce the diameter of the breakable pin, but there is a problem that the breakable pin is fatigued as described above and the breakable pin is broken by a load torque equal to or lower than the breaking torque.

The present invention solves the above-mentioned conventional problems,
An object of the present invention is to provide a power cutoff mechanism in a compressor that suppresses fatigue of an overload breakable material and can appropriately break the overload breakable material by a set overload torque in an abnormal state of the compressor. To do.

[0008]

Therefore, according to the invention of claim 1, in a compressor having a power cutoff mechanism, a drive force receiving body is provided at a protruding end of a rotary shaft, and a pulley and a drive force receiving body are provided. The bearing and the bearing are connected to each other via a plurality of overload rupturable members, and a gap that allows relative rotation between the pulley and the driving force receiver is provided in at least one coupling portion of each of the overload rupturable members. An elastic body for transmitting the driving force of the pulley to each overload rupturable material is provided in each gap, and each of the above elastic members is ruptured at different times with time. The amount of body deformation was set.

According to a second aspect of the invention, in the first aspect of the invention, the lengths of the plurality of gaps are set to be different, and the deformation amount of each elastic body is made different in proportion to the gap length. It is set.

According to a third aspect of the invention, in the second aspect of the invention, the elastic bodies are set to have the same spring constant. In the invention of claim 4, in the invention of claim 1, the lengths of the plurality of gaps are set to be the same, and the deformation amounts of the elastic bodies are set to be different.

According to a fifth aspect of the invention, in the invention of the fourth aspect, the elastic bodies are set to have the same spring constant. According to a sixth aspect of the present invention, in the first aspect of the present invention, each of the overload breakable materials is composed of a plurality of materials.

According to a seventh aspect of the present invention, in the invention according to any one of the first to sixth aspects, a plurality of overload breakable pins are provided on the driving force receiver in a direction orthogonal to the axis of the rotary shaft. A plurality of through-holes for loosely fitting the heads of the respective overload breakable pins are formed in the connecting board that is connected to the pulley, and is integrally formed with the pulley, and is arranged on the outer periphery of the driving force receiving body. A gap is formed between the head of each of the overload breakable pins and the step on the inner circumference of the through hole, and an elastic body is interposed in each gap.

According to an eighth aspect of the present invention, in the invention according to any one of the first to sixth aspects, a connecting board is integrally provided on a side wall of the pulley, and the driving force receiving body is provided on the connecting board. A plurality of overload breakable pins are connected to the side surface, and a plurality of overload breakable pins are connected to the connecting board in parallel to the axial direction of the rotating shaft. Through holes are formed, a gap is provided between the inner peripheral surface of each through hole and the outer peripheral surface of each overload breakable pin, and an elastic body is interposed in each gap.

According to a ninth aspect of the present invention, in a compressor having a power cutoff mechanism, a drive force receiving body is provided at the protruding end of the rotary shaft, and the pulley and the drive force receiving body are overloadable and rupturable. And a gap for allowing the relative rotation of the pulley and the driving force receiving body to be provided in at least one coupling portion of the overload breakable material, and the driving force of the pulley is exceeded in the gap. An elastic body that transmits the load-breakable material is interposed.

[0015]

According to the first aspect of the invention, the rotational driving force on the pulley side is transmitted to the driving force receiving body side through the plurality of elastic bodies and the overload rupturable member. When the load torque on the compressor side becomes equal to or greater than the set value, among the plurality of overload rupturable materials, the one in which the amount of deformation of the elastic body is set to be small is sequentially broken over time. When the last overload breakable material is broken, the power transmission between the pulley and the driving force receiver is cut off. By cutting off this power transmission, the adverse effect of the overload transmission from the compressor side to the external drive source side is avoided.

According to the first aspect of the present invention, when the load torque is less than or equal to the set value, the load torque changes due to load changes during start / stop of the compressor transmitted from the pulley to the rotary shaft and during normal operation. Is absorbed by the plurality of elastic bodies, so that repeated impact loads do not act on each overload rupturable material, and the durability is improved. Therefore, there is no possibility that the overload-breakable material will be broken by a load torque equal to or lower than the breaking torque. Further, in the invention according to claim 1, since the overload rupturable material is divided into a plurality of pieces and each rupturable material is sequentially ruptured with time, the rupture strength of one rupturable material is increased. (For example, a large diameter) can be set, and fatigue due to the load torque of the breakable material hardly occurs, and the durability can be improved also from this point.

According to the second aspect of the present invention, when the load torque on the compressor side exceeds the set value, the elastic body in the smallest gap is compressed to the maximum extent. At this time, since the elastic body in the other large gap is in the intermediate compression state, the overload torque acts intensively on the overload breakable material on the side of the smallest gap,
The breaking material is broken. Then, the elastic body in the gap of the intermediate length is compressed to the maximum. At this time, since the elastic body in the other gap having a large length is still in the intermediate compression state, the overload torque is concentrated on the overload rupturable material on the gap side of the intermediate length, and the rupturable material is Is broken. When the breaking operation is performed before and after the breaking operation and the last overloadable breaking material is broken, the power transmission between the pulley and the driving force receiving body is cut off. By cutting off this power transmission, the adverse effect of the overload transmission from the compressor side to the external drive source side is avoided. The other effects of the invention of claim 2 are the same as the effects of the invention of claim 1.

According to the third aspect of the present invention, since the elastic bodies are set to have the same spring constant, in addition to the effect of the second aspect of the invention, in the normal operating condition of the compressor, the excess pressure from the pulley is exceeded. The drive torque acting on the load-breakable material is made uniform, the power transmission is performed stably, the fatigue durability of each breakable material is improved, and the break timing can be set only by the size of the gap.

According to the fourth aspect of the present invention, when the load torque on the compressor side becomes equal to or greater than the set value, a plurality of overload rupturable materials corresponding to the elastic bodies having the smallest compression amount and the largest compression amount respectively are aged. Then, the power transmission between the pulley and the driving force receiving body is interrupted. By cutting off this power transmission, the adverse effect of the overload transmission from the compressor side to the external drive source side is avoided. The other operations of the invention of claim 4 are the same as the operations of the invention of claim 1.

According to the invention of claim 5, since each elastic body is set to have the same spring constant, in addition to the operation of the invention of claim 4, in the normal operating condition of the compressor, the excess pressure from the pulley is exceeded. The driving torque acting on the load-breakable material is made uniform, power transmission is stably performed, and the fatigue durability of each breakable material is improved.

According to the sixth aspect of the present invention, when the load torque on the compressor side exceeds the set value, a plurality of pairs of overload breakable materials are sequentially broken for each pair, and the pulley and the driving force receiving member are sequentially broken. Power transmission to and from the body is cut off. By cutting off this power transmission, the adverse effect of the overload transmission from the compressor side to the external drive source side is avoided. The other operations of the invention of claim 6 are the same as the operations of the invention of claim 1.

In the seventh aspect of the invention, when the pulley is rotated, the driving force receiving body and the rotating shaft are rotated from the connecting board through the plurality of elastic bodies and the overload breakable pins. When the load of the compressor exceeds the set value, the pin with the smaller spacing between the overloadable rupturable pins with the elastic body is ruptured first, and then the overload rupturable in the order of increasing spacing. When the pin is broken and the last pin is broken, the power transmission between the pulley and the driving force receiver is interrupted. By cutting off this power transmission, the adverse effect of the overload transmission from the compressor side to the external drive source side is avoided.

The construction in which the overload breakable pin is connected to the driving force receiving body and the elastic body is interposed between the head portion of the pin and the stepped portion on the side of the connecting board is simple, and the working and assembling work is simple. It's easy.

In the invention of claim 8, when the pulley is rotated, the driving force receiving body and the rotating shaft are rotated from the connecting board through the overload breakable pin and the plurality of elastic bodies. When the load of the compressor exceeds the set value, the pin with the smaller spacing between the overloadable rupturable pins with the elastic body is ruptured first, and then the overload rupturable in the order of increasing spacing. When the pin is broken and the last pin is broken, the power transmission between the pulley and the driving force receiver is interrupted. By cutting off this power transmission, the adverse effect of the overload transmission from the compressor side to the external drive source side is avoided.

The structure in which the overload breakable pin is connected to the side surface of the connecting substrate and the elastic body is interposed between the outer peripheral surface of the pin and the through hole of the driving force receiving body is simple, and processing and Assembly work becomes easy.

According to the ninth aspect of the invention, during normal operation, the rotational driving force on the pulley side is transmitted to the driving force receiving body side via the elastic body and the overload rupturable member. When the load torque on the compressor side exceeds the set value, the elastic body is compressed to the maximum, the overload breakable material is broken, and the power transmission between the pulley and the driving force receiving body is cut off. By cutting off this power transmission, the adverse effect of the overload transmission from the compressor side to the external drive source side is avoided.

In the invention according to claim 9, when the load torque is equal to or less than a set value, fluctuations in the load torque due to load fluctuations during start / stop of the compressor transmitted from the pulley to the rotary shaft and during normal operation. Is absorbed by the elastic body, so that repeated impact loads do not act on the overload rupturable material, and the durability is improved. Therefore, there is no possibility that the overload-breakable material will be broken by a load torque equal to or lower than the breaking torque.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment embodying the present invention will now be described with reference to FIG.
~ It demonstrates based on FIG. As shown in FIG. 1, a front housing 2 is joined to the front end of the cylinder block 1, and a rear housing 3 is joined to the rear end of the cylinder block 1. A rotary shaft 4 is rotatably supported between a front housing 2 forming a crank chamber 2-1 and a cylinder block 1. The front end of the rotary shaft 4 projects from the crank chamber 2-1 to the outside.

A support cylinder 2-2 is formed integrally with the front housing 2, and an angular bearing 5 for receiving both the axial load and the radial load is formed in the support cylinder 2-2 in the axial direction of the rotary shaft 4. It is slidably supported. A pulley 6 is fixed to the outer ring of the angular bearing 5. The pulley 6 is composed of a connecting board 6-1 fixed to the outer ring of the angular bearing 5, and a pulley body 6-2 fitted and fixed to the outer peripheral surface of the connecting board 6-1. The pulley body 6-2 is connected via a belt 7 to a vehicle engine (not shown) that is an external drive source.

Next, the power cutoff mechanism K will be described.
A driving force receiving body 8 is screwed to a projecting end portion 4-1 of the rotary shaft 4 projecting from the crank chamber 2-1 to the outside so that the driving force receiving body 8 cannot slide in the axial direction and can rotate synchronously. Rotating shaft 4
A lock bolt 9 is screwed onto the tip surface of the.

As shown in FIGS. 1 and 2, a clearance C is provided between the outer peripheral surface of the driving force receiving body 8 and the inner peripheral surface of the connecting substrate 6-1.
₁ is formed, and notch recesses 8-1 are formed at two locations on the outer peripheral surface of the driving force receiving body 8. Further, a through hole 6-3 is formed in the connecting board 6-1 corresponding to the notch recess 8-1, and the first breakable pin 1 as an overload breakable material is formed in the through hole 6-3.
0, the second rupturable pin 11 is loosely penetrated, and the tip screw portions 10-1 and 11-1 are formed in the vertical wall surface of the cutout recess 8-1 of the driving force receiving body 8 in the screw hole 8-. It is screwed to 2. The heads 10-2 and 11-2 of both the breakable pins 10 and 11 are fitted into the large-diameter portion 6-4 of the through hole 6-3, and the heads 10-2 and 1
A first spring 12-1 and a second spring 12-2 as disc spring type elastic bodies are interposed between 1-2 and the step portion 6-5 of the through hole 6-3.

The driving force associated with the rotation of the pulley 6 acts on the rupturable pins 10 and 11 as a tensile load, and the springs 12-1 and 12
-2 is arranged so as to elastically deform in the pulling direction. The rotation of the vehicle engine is transmitted to the pulley 6 via the belt 7, and the rotation of the pulley 6 is the first spring 12-1 and the second spring 12-.
2, transmitted to the rotary shaft 4 via the first breakable pin 10, the second breakable pin 11, and the driving force receiving body 8. A disc spring type preloading spring 13 is interposed between the inner ring of the angular bearing 5 and the front housing 2. The spring force of the preload applying spring 13 is the angular bearing 5, the connecting substrate 6-1, the first spring 12-1, the second spring 12-2, the first breakable pin 10, the second breakable pin 11 and the driving force. Acceptor 8
Is transmitted to the rotary shaft 4 via the shaft, and biases the rotary shaft 4 in a direction projecting from the front housing 2.

Fracturable portions 10-3 and 11-3 are formed in the intermediate portions of both the frangible pins 10 and 11, and the cross-sectional areas of both the frangible portions are set to be the same, and the overload torque equal to or more than the set value is set. When the breakable portions 10-3 and 11-3 act, the breakable portions 10-
3 and 11-3 are designed to be broken. A first gap G1 between the head portion 10-2 of the first breakable pin 10 and the step portion 6-5.
Is the head portion 11-2 and the step portion 6-5 of the second breakable pin 11.
It is set to be smaller than the second gap G2 between and. Further, the first spring 12-1 and the second spring 12-2 are interposed in a non-compressed state when the compressor is in a stopped state, and the lengths of both springs 12-1 and 12-2 are equal to the first and second gaps. It is set the same as G1 and G2. Further, as shown in FIG. 6, the spring constants of the first spring 12-1 and the second spring 12-2 are set to be the same.

Next, the structure of the compressor body will be described. The rotary support 14 is fixed to the rotary shaft 4. A swash plate 15 is supported on the rotary shaft 4 so as to be slidable and tiltable in the axial direction of the rotary shaft 4. As shown in FIG. 7, the swash plate 15 is moved in the axial direction of the rotary shaft 4 by the cooperation of the support arm 14-1 on the rotary support 14 and the pair of guide pins 16 and 17 having one end fixed to the swash plate 15. Tiltable and rotating shaft 4
It is possible to rotate integrally with. The tilting of the swash plate 15 is guided by the slide guide relationship between the support arm 14-1 and the guide pins 16 and 17, and the slide support action with the rotating shaft 4.

The rear end of the rotary shaft 4 has a deep groove ball bearing member 18
And, it is supported by the inner peripheral surface of the accommodation hole 20 in the cylinder block 1 via the blocking body 19. An intake passage 21 is formed in the center of the rear housing 3. The suction passage 21 communicates with the accommodation hole 20, and the tip of the blocking body 19 can contact the positioning surface 22 around the opening of the suction passage 21.
When the tip of the blocking body 19 abuts the positioning surface 22, the blocking body 19 is restricted from moving in the direction away from the swash plate 15, and the communication between the suction passage 21 and the accommodation hole 20 is blocked.

Due to the decrease of the swash plate inclination angle, the swash plate 15 becomes the blocking member 1.
As it moves to the 9 side, the swash plate 15 comes into contact with the transmission cylinder 23 and pushes the transmission cylinder 23 and the deep groove ball bearing member 18 toward the positioning surface 22 side. The deep groove ball bearing member 18 receives a load not only in the radial direction of the rotating shaft 4 but also in the axial direction. Therefore, the blocking body 19 is urged toward the positioning surface 22 against the spring force of the suction passage opening spring 24, and the blocking body 19 is blocked.
The tip of the abuts on the positioning surface 22.

The minimum inclination angle of the swash plate 15 is slightly larger than 0 °. This minimum tilt angle state is brought about when the blocking body 19 is arranged in the closed position that blocks the communication between the suction passage 21 and the accommodation hole 20. The maximum inclination of the swash plate 15 is the rotation support 14
It is regulated by the contact between the inclination regulating protrusion 14-2 and the swash plate 15.

The rotational movement of the swash plate 15 is converted via the shoes 25 into the forward and backward reciprocating movement of the single-headed piston 26 in the cylinder bore 1-1. As shown in FIGS. 1 and 8, the rear housing 3 has a suction chamber 3-1 and a discharge chamber 3-2 defined therein. The refrigerant gas in the suction chamber 3-1 pushes the suction valve 28 away from the suction port 27 by the returning movement of the single-headed piston 26 and flows into the cylinder bore 1-1. The refrigerant gas flowing into the cylinder bore 1-1 pushes the discharge valve 30 out of the discharge port 29 by the forward movement of the single-headed piston 26, and the discharge chamber 3
It is discharged to -2.

A thrust bearing 31 is interposed between the rotary support 14 and the front housing 2. The compression reaction force from the cylinder bore 1-1 is generated by the single-headed piston 26,
It is received by the front housing 2 via the shoe 25, the swash plate 15, the guide pins 16 and 17, the rotary support 14 and the thrust bearing 31.

The suction chamber 3-1 is provided with a receiving hole 20 through the passage 32.
Is in communication with. When the blocking body 19 is arranged in the closed position, the passage 32 is blocked from the suction passage 21. Rotating shaft 4
A passage 33 is formed inside. The passage 33 communicates the crank chamber 2-1 with the inside of the cylinder of the blocking body 19. Blocker 1
As shown in FIG. 1, a pressure release port 19-1 is provided at the tip of 9 so as to penetrate therethrough. The pressure release port 19-1 communicates the accommodation hole 20 with the inside of the cylinder of the blocking body 19.

The crank chamber 2-1 and the discharge chamber 3-2 are connected by a pressure supply passage 34. An electromagnetic opening / closing valve 35 is interposed on the pressure supply passage 34. The valve body 35-2 closes the valve hole 35-3 by exciting the solenoid 35-1 of the electromagnetic opening / closing valve 35. When the solenoid 35-1 is demagnetized, the valve body 35-2 opens the valve hole 35-3.

A suction passage 21 for introducing the refrigerant gas into the suction chamber 3-1 and a discharge port 1-2 for discharging the refrigerant gas from the discharge chamber 3-2.
And are connected by an external refrigerant circuit 36. A condenser 37, an expansion valve 38 and an evaporator 39 are provided on the external refrigerant circuit 36. The expansion valve 38 controls the refrigerant flow rate according to the fluctuation of the gas pressure on the outlet side of the evaporator 39. A temperature sensor 40 is installed near the evaporator 39. The control computer C _O controls excitation / demagnetization of the solenoid 35-1 based on the detected temperature information obtained from the temperature sensor 40. The control computer C _O causes the solenoid 35 to operate when the detected temperature falls below the set temperature while the air conditioner operation switch 41 is ON.
Command degaussing -1. The temperature equal to or lower than the preset temperature reflects a situation in which frost is likely to occur in the evaporator 39.
Further, the control computer C _O is an air conditioner operation switch 41.
Under the ON state of the solenoid 35, the solenoid 35 is detected by the specific rotation speed fluctuation detection information from the rotation speed detector 42 of the vehicle engine.
Degauss -1. Further, the control computer C _O demagnetizes the solenoid 35-1 by turning off the air conditioner operation switch 41. When the solenoid 35-1 is demagnetized, the pressure supply passage 34 opens, and the discharge chamber 3-2 and the crank chamber 2-1 communicate with each other. Therefore, the refrigerant gas in the discharge chamber 3-2 flows into the crank chamber 2-1, and the pressure in the crank chamber 2-1 increases. The tilt angle of the swash plate 15 shifts to the minimum tilt side due to the pressure increase in the crank chamber 2-1. When the tip of the blocking body 19 comes into contact with the positioning surface 22, the swash plate inclination angle becomes minimum, and the refrigerant gas from the external refrigerant circuit 36 to the suction chamber 3-1 is blocked.

Since the minimum inclination of the swash plate is not 0 °, the discharge from the cylinder bore 1-1 to the discharge chamber 3-2 is performed even when the inclination of the swash plate is minimum. The refrigerant gas in the suction chamber 3-1 is sucked into the cylinder bore 1-1 and discharged into the discharge chamber 3-2. That is, when the swash plate tilt angle is at a minimum, it passes through the discharge chamber 3-2, the pressure supply passage 34, the crank chamber 2-1, the passage 33, the pressure release port 19-1, the suction chamber 3-1, and the cylinder bore 1-1. There is a circulation passage inside the compressor. The lubricating oil flowing with the refrigerant gas lubricates the inside of the compressor via the circulation passage.
There is a pressure difference between the discharge chamber 3-2, the crank chamber 2-1, and the suction chamber 3-1. The pressure difference and the passage cross-sectional area at the pressure release passage 19-1 stably hold the swash plate 15 at the minimum inclination angle.

When the solenoid 35-1 is excited, the pressure supply passage 34 is closed. Since there is a pressure difference between the inside of the crank chamber 2-1 and the inside of the suction chamber 3-1, the pressure in the crank chamber 2-1 is reduced based on the pressure released through the passage 33 and the pressure release port 19-1. Do it. Due to this pressure reduction, the tilt angle of the swash plate 15 shifts from the minimum tilt angle to the maximum tilt angle.

In the compressor which performs such an operation, the load torque on the compressor side from the rotary shaft 4 to the driving force receiving body 8, the first and second rupturable pins 10, 11 and Pulley 6 via first and second springs 12-1 and 12-2
Is transmitted to The fluctuation of the load torque at the time of starting and stopping the compressor or the fluctuation of the compression capacity is caused by the spring 12-
Since it is absorbed by the elastic deformation of 1 and 12-2, repeated impact load does not act on the first and second breakable pins 10 and 11, and the durability is improved. 63-1
Unlike the overload rupturable material disclosed in Japanese Patent No. 9083, the first and second rupturable pins 10 and 11 do not repeatedly exert a load torque equal to or less than the set overload torque, The breakable pins 10 and 11 do not fatigue.

When the load torque on the compressor side exceeds a set value, if this excessive load torque spreads to the vehicle engine side, the vehicle engine may stall or
The belt 7 may be broken. In the first embodiment, when an excessive load torque is generated, the overload torque causes the first spring 12-1 in the first gap G1 to reach the maximum compression state (that is, elastic deformation is completed) as shown in FIG. The overload torque of the pulley 6 concentrates on the first breakable pin 10 via the first spring 12-1. Therefore, the first breakable pin 1
The breakable portion 10-3 of No. 0 is broken as shown in FIG. Immediately after that, as shown in FIG. 4, the second spring 12-2 is in the maximum compression state, and all the overload torque acts on the second breakable pin 11, so that the breakable portion 11 of the breakable pin 11 is affected. -3
Is broken, and as a result, the pulley 6 is idled as shown in FIG. Therefore, the excessive load torque does not spread to the vehicle engine side, and the engine stall does not occur. It should be noted that the broken pieces of the pins 10 and 11 are the spring 1
It comes out from the through hole 6-3 by 2-1 and 12-2.

Further, in the above-described embodiment, the first and second breakable pins 10 and 11 are used, and the breakable pins 10 and 11 are used.
Since 11 is broken back and forth with time, the breaking strength (for example, pin diameter) of one breakable pin 10 can be set to be large. Therefore, it is possible to improve durability against load torque repeatedly applied during normal operation. If the plurality of breakable pins 10 and 11 are configured to be broken at the same time, each breakable pin 10 and 11 is broken.
It is necessary to reduce the rupture strength of the rupturable pin, and therefore the rupturable pin easily fatigues due to the load torque during normal operation, which causes a problem in durability.

By the way, the first and second springs 12-
As shown in FIG. 6, 1 and 12-2 have the same spring constant and use load characteristics Y-1 and Y-2. Spring 1
2-1 becomes the maximum compression state at L1, the load on the overload breakable pin 10 reaches the breaking load P, and the overload breakable pin 1
0 breaks. The spring 12-2 is in the maximum compression state at L2, the load on the overload breakable pin 11 reaches the breaking load P, and the overload breakable pin 11 breaks. In the above embodiment, since the springs having the same spring constant are used, the gap G1,
The breakage timing of the pins 10 and 11 can be easily set only by changing the size of G2.

The screw portions 10-1 and 11-1 of the overload breakable pins 10 and 11 are screwed into the driving force receiving body 8, and the head portions 10-2 and 11-2 of the pin and the connecting board 6 are connected. The configuration in which the springs 12-1 and 12-2 are interposed in the stepped portion 6-5 on the -1 side is simple, and processing and assembling work are easy. Further, since the pins 10 and 11 are assembled in the direction orthogonal to the axis of the rotating shaft 4, the size of the compressor in the axial direction can be shortened and the size can be reduced.

Since the rotating shaft 4 may be displaced in the axial direction and rattling, it is necessary to apply a preload to the rotating shaft 4 in the axial direction to prevent the rattling. In the compressor of the first embodiment, if a preload is applied in the direction in which the rotary shaft 4 projects from the front housing 2, this preload is received by the front housing 2 via the thrust bearing 31. Preloading spring 13
Is the angular bearing 5, the pulley 6,
A preload is applied to the rotary shaft 4 via the springs 12-1 and 12-2, the breakable pins 10 and 11, and the driving force receiving body 8. The magnitude of the preload of the preload applying spring 13 depends on the screwing position of the lock bolt 9, that is, the tip surface of the rotating shaft 4 and the pressing plate 4-3.
It is adjusted by a spacer (not shown) interposed between and.

Next, a second embodiment shown in FIGS. 9 to 11 will be described. In this embodiment, the connecting substrate 6-1 is formed in a disk shape, and screw holes 6-6 are formed at two positions thereof, and the first and second breakable pins as overload breakable pins are formed in both screw holes. The threaded portions 10A-1 and 11A-1 of the pins 10A and 11A are the rotation shaft 4
It is screwed in parallel with. Further, the side surface of the disk-shaped driving force receiving body 8 is brought into contact with the side surface of the connecting substrate 6-1 and the receiving body 8 has a first through hole that loosely penetrates both the breakable pins 10A and 11A. 8-3 and a second through hole 8-4 are formed, and the first and second gaps G1 and G1 are formed between the breakable pins 10A and 11A and the through holes 8-3 and 8-4. First and second gaps G1 and G2 having a size different from that of G2 are formed. An annular first elastic body 51 and a second elastic body 52 made of rubber are interposed in the gaps G1 and G2.
The outer peripheral portions of both elastic bodies 51, 52 are engaged with annular grooves 8-5 formed on the inner peripheral surfaces of the first through hole 8-3 and the second through hole 8-4. The driving force acts on the breakable pins 10A and 11A as a shearing load, and the elastic bodies 51 and 52 are set to elastically deform in the radial direction. The other structure of this embodiment is the same as that of the first embodiment.

As described above, the load torque on the compressor side fluctuates, and if this fluctuation is transmitted as it is to the vehicle engine side, the vehicle engine causes an undesired rotational speed fluctuation. The first elastic body 51 and the second elastic body 52 reduce the fluctuation of the load torque on the compressor side and transmit it to the pulley 6 side, and the fluctuation of the rotation speed of the vehicle engine is suppressed.

When the load of the compressor exceeds the set value,
As shown in 1, the first elastic body 51 completes elastic deformation.
Since the second elastic body 52 is in the process of elastic deformation, the load concentrates on the first breakable pin 10A. Therefore, the first breakable pin 10A receives a shearing force at the intermediate portion and is broken. Immediately after this rupture, the second elastic body 52 completes elastic deformation, and excessive load torque is concentrated on the rupturable pin 11A,
The pin 11A is broken and the pulley 6 idles. Therefore, the excessive load torque does not spread to the vehicle engine side, and the engine stall does not occur.

In the above embodiment, the first and second breakable pins 10A and 11A are used, and each breakable pin 1 is used.
Since 0A and 11A are made to break before and after the passage of time, the breaking strength of one breakable pin 10A can be set to a large value. Therefore, fatigue resistance against drive torque repeatedly applied during normal operation is enhanced, and durability can be improved.

Both of the breakable pins 10A and 11A are screwed into the connecting board 6-1 to make the diameters of the first and second through holes 8-3 and 8-4 large and small. The configuration in which the first and second elastic bodies 51 and 52 having different wall thicknesses are fitted in the two gaps G2 is simple and easy to process and assemble.

Next, a third embodiment shown in FIG. 12 will be described. In this embodiment, rubber rings 53 and 54 are used instead of the disc springs as the first and second elastic bodies interposed in the first gap G1 and the second gap G2 described in the first embodiment. . The rubber rings 53 and 54 have the same thickness as the gaps G1 and G2, and the rubber ring 53 is thinner than the rubber ring 54. In this embodiment, the fluctuation of the driving torque is absorbed by the rubber ring during the normal operation of the compressor, but when an excessive load torque acts on the first and second breakable pins 10 and 11, the disc spring is Since the deformation at the time of compression is performed more smoothly than that of the above, the breakable pins 10 and 11 can be stably broken. Other configurations, operations and effects of this embodiment are similar to those of the first embodiment.

Next, a fourth embodiment shown in FIG. 13 will be described. In this embodiment, in the first embodiment, the first gap G1 and the second gap G2 are set to have the same length, and
The plate thickness of the first elastic body 12-1 is set to be larger than the plate thickness of the second elastic body 12-2. The other structure is similar to that of the first embodiment.

Therefore, in the fourth embodiment, when the load on the compressor side exceeds the set value, the first elastic body 12-1 having a larger plate thickness than the second elastic body 12-2 is first compressed to the maximum compression. When the first breakable pin 10 is broken in the state (that is, the elastic deformation is completed) and then the second elastic body 12-2 is in the maximum compression state, the second breakable pin 11 is Be broken.
Other operational effects of the fourth embodiment are similar to those of the first embodiment.

In the fourth embodiment, the spring constants of the first and second elastic bodies 12-1 and 12-2 need not be the same, but in the case of the same, the load torque during normal operation is The impact due to the fluctuation is evenly transmitted to the pins 10 and 11, and the power can be transmitted smoothly. Further, the impacts on both pins 10 and 11 are alleviated equally, and the durability of both pins against impact fatigue is improved.

Next, a fifth embodiment shown in FIG. 14 will be described. In this embodiment, a pair of the first and second breakable pins 10 and 11 are provided in the second embodiment. The other structure is the same as that of the second embodiment.

Therefore, in the fifth embodiment, when the load torque on the compressor side exceeds the set value, the pair of first breakable pins 10 and 10 are first broken at the same time, and then the pair of second breakable pins. The breaking pins 11, 11 are broken at the same time. In this embodiment, each of the first and second breakable pins 10 and 11 is equivalent to one formed by bundling a plurality of rod-shaped members or plate-shaped members. Other operational effects of the fourth embodiment are similar to those of the first embodiment.

Next, a sixth embodiment shown in FIG. 15 will be described. In this embodiment, only the single gap G1, the elastic body 51 and the breakable pin 10 are provided in the second embodiment. The other structure is the same as that of the second embodiment.

Therefore, in the sixth embodiment, the impact due to the fluctuation of the driving torque during the normal operation is caused by one elastic body 5.
1 and the load torque on the compressor side exceeds the set value, the elastic body 51 is in the maximum compression state and the breakable pin 10
Is broken and the power is immediately cut off. The other operational effects of the sixth embodiment are similar to those of the second embodiment.

The present invention can be further embodied as follows. (1) Although the first and second breakable pins 10 and 11 are used in the first to fourth embodiments, the number of breakable pins is three or more, and the breakable pins move forward and backward with time. Set the gap length and the maximum compression amount of the elastic body so that they will fracture sequentially. In this case as well, the same operational effects as the above-described embodiment are obtained. (2) The driving force receiving body 8 is formed integrally with the rotating shaft. (3) In the above embodiment, the elastic body is provided only at one end of each of the pins 10 and 11, but it should also be provided at the other end. (4) In FIG. 13, the elastic body 12-1 made of a disc spring,
Use rubber elastic body instead of 12-2. In this case, the materials and characteristics of the rubbers are set so that the maximum compression amounts of the two rubbers are different so that the pins 10 and 11 are broken back and forth. (5) Apply the configuration having a plurality of pairs of pins 10 and 11 shown in FIG. 14 to the first and third embodiments. (6) Apply the configuration in which the pin 10 and the elastic body 51 shown in FIG. 15 are united to the first embodiment and the third embodiment. (7) In the first to fifth embodiments, the pins 10 and 11 are designed to be fractured back and forth with time. However, the gap length and the maximum compression amount of the elastic body are set so that they are fractured simultaneously. To do. Also in this case, the fatigue of the pins 10 and 11 against the impact can be suppressed, and the power can be cut off when the load torque exceeds the set value. (8) In the above embodiment, the pin is provided with a rupturable portion, but this portion has a caulking structure so that the pin is disconnected when an overload torque is applied. In this specification, such a structure is also included in the breakable portion.

The technical ideas other than the claims that can be understood from the above-described embodiments will be described below along with their effects. In claim 2, the springs 12-1 and 12-2 are made of rubber.

In this case, since the deformation at the time of compression is carried out more smoothly than the elastic body made of the disc spring, the breakable pins 10, 11 can be stably broken.

[0067]

As described in detail above, since the present invention is constructed as described in the section of the claims, it has the following effects.

According to the first and sixth aspects of the present invention, fatigue of the overload rupturable material can be suppressed to enhance durability, and the overload rupturable material can be appropriately ruptured by the set overload torque. It is possible to improve the durability by increasing the diameter of the fracture portion of a single overload rupturable material.

According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the breakage timing of each overloadable breakable material can be easily set only by making each gap length different. According to the invention described in claim 3, in addition to the effect of the invention described in claim 2, in the normal operating state of the compressor, the load torque acting on each of the overload breakable materials is made uniform to stabilize the power transmission. It is possible to improve the fatigue durability of each overloadable material.

According to the invention described in claim 4, in addition to the effect of the invention described in claim 1, the breakage timing of each overloadable breakable material can be easily set only by changing the maximum compression amount of each elastic body. be able to. According to the invention of claim 5, in addition to the effect of the invention of claim 4, in the normal operating state of the compressor, the load torque acting on each of the overload breakable materials is made uniform to stabilize the power transmission. It is possible to improve the fatigue durability of each overloadable material.

According to the inventions of claims 7 and 8, in addition to the effects of the invention of any one of claims 1 to 6, the structure is simplified, the processing and the assembling work can be easily performed, and the power shutoff is performed. It is possible to reduce the size of the compressor by reducing the axial dimension of the mechanism.

According to the ninth aspect of the present invention, fatigue of the overload-breakable material can be suppressed to improve durability, and the overload-rupturable material can be properly broken by the set overload torque.

[Brief description of drawings]

FIG. 1 is a side sectional view of an entire compressor of a first embodiment embodying the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a partial cross-sectional view of a power cutoff mechanism.

FIG. 4 is a partial sectional view of a power cutoff mechanism.

FIG. 5 is a partial cross-sectional view of a power cutoff mechanism.

FIG. 6 is a graph showing spring characteristics of a disc spring.

7 is a sectional view taken along line BB of FIG.

8 is a cross-sectional view taken along the line CC of FIG.

FIG. 9 is an enlarged side sectional view of an essential part showing a second embodiment.

10 is a sectional view of only a main part taken along the line DD of FIG.

FIG. 11 is a partial cross-sectional view of the power cutoff mechanism.

FIG. 12 is a cross-sectional view of the essential parts of the third embodiment.

FIG. 13 is a cross-sectional view of the essential parts of the fourth embodiment.

FIG. 14 is a cross-sectional view of the essential parts of the fifth embodiment.

FIG. 15 is a sectional view of a main portion of a sixth embodiment.

[Explanation of symbols]

2 ... Front housing, 4 ... Rotating shaft, 4-1 ... Projection end part, 6 ... Pulley, 6-1 ... Connection board, 6-3 ... Through hole, 6-4
... Large diameter part, 6-5 ... Step part, 8 ... Driving force receiver, 8-3,8
-4 ... First and second through holes, 10, 11 ... First and second breakable pins as overload breakable materials, 12-1, 12-2, ... First and second springs, 51 ... 1 elastic body, 52 ... second elastic body,
53, 54 ... Rubber rings as first and second elastic bodies, G1, G2 ... First and second gaps, K ... Power interruption mechanism.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinichi Ogura, 2-chome, Toyota-cho, Kariya city, Aichi stock company Toyota Industries Corp.

Claims (9)

[Claims] 1. A pulley, which is rotated by a driving force of an external drive source, is mounted on a housing, and when a torque of a set value or more is applied between a protruding end of a rotating shaft supported by the housing and the pulley. In a compressor having a power cutoff mechanism for cutting off power, a drive force receiver is provided at a protruding end of the rotary shaft,
The pulley and the driving force receiving member are connected to each other via a plurality of overload rupturable materials, and the relative rotation between the pulley and the driving force receiving member is provided in at least one connecting portion of each of the overload rupturable members. There are gaps that allow movement, and elastic bodies that transmit the driving force of the pulley to each overload rupturable material are interposed in each gap, and the plurality of overload rupturable materials are broken at different times with time. A power cutoff mechanism in a compressor in which the amount of deformation of each elastic body is set as described above. 2. The power of the compressor according to claim 1, wherein the lengths of the plurality of gaps are set to be different, and the deformation amounts of the elastic bodies are set to be different in proportion to the gap length. Shutoff mechanism. 3. The power cutoff mechanism for a compressor according to claim 2, wherein the elastic bodies are set to have the same spring constant. 4. The power cutoff mechanism for a compressor according to claim 1, wherein the lengths of the plurality of gaps are set to be the same, and the deformation amounts of the elastic bodies are set to be different. 5. The power cutoff mechanism for a compressor according to claim 4, wherein the elastic bodies are set to have the same spring constant. 6. The power cutoff mechanism for a compressor according to claim 1, wherein each of the overload breakable materials is composed of a plurality of materials. 7. A plurality of overload rupturable pins are respectively connected to the driving force receiving body in a direction orthogonal to the axis of the rotating shaft, are integrally formed with a pulley, and A plurality of through-holes that loosely fit the heads of the overload-breakable pins are provided on the connection board arranged on the outer circumference, and the heads of the overload-breakable pins and the inner circumferences of the through-holes are provided. 7. The power cutoff mechanism for a compressor according to claim 1, wherein a gap is formed between the step portion and an elastic body is interposed in each gap. 8. A connection board is integrally provided on a side wall of the pulley, the driving force receiver is in contact with a side surface of the connection board, and a plurality of overload breakable pins are rotated on the connection board. The drive force receiving body has a plurality of through holes that are connected parallel to the axial direction of the shaft and that penetrate each breakable pin loosely. 7. A power cutoff mechanism for a compressor according to claim 1, wherein a gap is provided between an outer peripheral surface of the breaking pin and an elastic body is interposed in each gap. 9. A pulley, which is rotated by a driving force of an external drive source, is mounted on a housing, and when a torque of a set value or more is applied between a protruding end of a rotating shaft supported by the housing and the pulley. In a compressor having a power cutoff mechanism for cutting off power, a drive force receiver is provided at a protruding end of the rotary shaft,
The pulley and the driving force receiver are connected to each other via an overload rupturable material, and at least one connecting portion of the overload rupturable material allows relative rotation of the pulley and the driving force receiver. A power cut-off mechanism in a compressor in which a gap is provided, and an elastic body for transmitting the driving force of the pulley to the overload rupturable material is interposed in the gap.