JPH09222076A - Reciprocating type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reciprocation type compressor to reduce the generation of a rotation n-th component of a torque fluctuation corresponding to the num ber of cylinders and reduce the generation of noise and vibration. SOLUTION: Cylinder bores 12a (11a)-12e (11e) are formed in such a manner to oppose to a pair of cylinder blocks, and a double end piston is contained in the cylinder bores 12a (11a) 12e (11e) to partition a compression chamber. By shaving off the head of the double end piston by a given length, the value of a dead volume of each compression chamber is roughly varied into two groups. The large compression chambers 29b and 30b of the dead volume are arranged in such a manner to be continued in the arrangement direction of a compression chamber. The dead volumes of the compression chambers on both sides of the double end piston are set to the same as each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating compressor used in, for example, a vehicle air conditioner.

[0002]

2. Description of the Related Art In a reciprocating compressor of this type, a drive shaft is supported inside a housing and a crank chamber is formed. A plurality of cylinder bores are arranged in parallel to each other to surround the drive shaft in a cylinder block constituting a part of the housing. A piston is housed in the cylinder bore so as to be able to reciprocate, and a compression chamber is defined. A swash plate is integrally rotatably mounted on the drive shaft, and the piston is reciprocated in conjunction with the rotation of the swash plate to compress the refrigerant gas in the compression chamber.

[0003] During operation of the compressor, a compression reaction force acts on each of the pistons in accordance with the compression operation. This compression reaction force acts on the drive shaft via the swash plate, causing torque fluctuations. This torque fluctuation becomes an exciting force of torsional vibration of the drive shaft-clutch system. Here, when a fast Fourier transform (FFT) analysis is performed on the sum of the torque fluctuations, in other words, the sum of the compression reaction forces generated in the respective compression chambers, a wide range of frequency components from the 0th order to a considerably higher order is obtained.
Among these frequency components, the main component is the number of cylinders n
Is the n-th order component of rotation. If the frequency of the rotation n-order component and the like is close to the natural frequency of the compressor and the auxiliary equipment connected thereto, noise due to the resonance phenomenon occurs, and the noise level in the passenger compartment is reduced. Was causing it to rise.

In order to solve such a problem, for example, Japanese Unexamined Utility Model Publication No. 1-160180 discloses that in a swinging swash plate type variable displacement compressor, when the arrangement of the cylinder bores is unequal due to the structure, a part of the variable displacement compressor is required. A configuration in which the dead volume of the compression chamber in the cylinder bore is changed is disclosed. Note that the dead volume is the volume of the compression chamber when the piston reaches the top dead center. In this reciprocating compressor, the dead volume is formed by cutting off the surface of the piston by a predetermined length. In the compression chamber in which the dead volume has been expanded, the transition curve between the volume and the pressure is changed with the expansion of the dead volume. Then, the compression reaction force generated in the compression chamber is reduced, and the sum of the compression reaction forces acting on the swinging swash plate is always equal, so that the generation of torsional vibration and noise is reduced.

[0005]

However, the above publication only discloses changing the dead volume of some of the cylinder bores in order to reduce the torsional vibration of the compressor. That is, there is no disclosure or suggestion of the regularity for taking measures against the torque fluctuation of the drive shaft. For this reason, there has been a problem that the torque fluctuation cannot be sufficiently reduced, and the generation of noise and vibration may not be sufficiently suppressed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a reciprocating compressor in which the excitation force of torsional vibration is reduced, the rotational nth order component of torque fluctuation corresponding to the number of cylinders n is reduced, and noise and vibration are less generated. Is to do.

[0007]

In order to achieve the above object, in the invention described in claim 1, a plurality of cylinder bores are arranged in a cylinder block so as to surround the drive shaft,
In a reciprocating compressor in which a piston is reciprocally housed in the cylinder bore to define a compression chamber, each compression chamber has a predetermined dead volume, and each compression chamber has a dead volume. At least two of the compression chambers form a group of large dead volume compression chambers in which the value of the dead volume is set to be larger than that of other compression chambers in the same array plane, and the other compression chambers are set as small dead volume compression chambers. It is configured as a group, and the difference between the dead volume value of the large dead volume compression chamber and the dead volume value of the small dead volume compression chamber is set to be larger than the difference of the dead volume values within each dead volume compression chamber group. At the same time, the large dead volume compression chamber is continuous in the array direction of the cylinder bores. In which are arranged in.

According to a second aspect of the invention, in the reciprocating compressor according to the first aspect, the value of the minimum dead volume in the group of the large dead volume compression chambers is the group of the small dead volume compression chambers. It is formed so as to be 2 to 7 times the maximum dead volume value.

According to a third aspect of the present invention, in the reciprocating compressor according to the first or second aspect, the maximum dead volume value and the minimum dead volume value between the compression chambers are the minimum dead volume values. The difference is 1% or more of the volume at the bottom dead center of the compression chamber having the volume.

[0010] According to the invention described in claim 4, claims 1 to 3 are provided.
In the reciprocating compressor according to any one of the above, the value of the maximum dead volume and the value of the minimum dead volume between the respective compression chambers are 10 times the volume at the time of the bottom dead center of the compression chamber having the minimum dead volume. % Or less.

According to the fifth aspect of the invention, the first to fourth aspects are provided.
In the reciprocating compressor according to any one of the above, the dead volume in the group of the large dead volume compression chambers is different from each other.

According to the sixth aspect of the present invention, the first to fifth aspects are provided.
In the reciprocating compressor according to any one of 1, the cylinder bores are formed to face each other in the front-rear direction, the piston is configured in a double-headed type, and a predetermined dead volume is formed in each compression chamber on both front and rear sides. is there.

According to a seventh aspect of the invention, in the reciprocating compressor according to the sixth aspect, the dead volume on the front side and the dead volume on the rear side are set to the same size for one double-headed piston. It was formed.

According to the invention described in claim 8, in claims 1 to 7,
In the reciprocating compressor according to any one of items 1 to 5, the dead volume of each compression chamber is formed by changing the shape of the piston.

Therefore, in the reciprocating compressor configured as described above, each compression chamber on the array surface of the cylinder bores (which indicates the group of cylinder bores corresponding to one valve plate) has a large dead volume compression chamber and a small dead volume compression chamber. It is divided into two groups, the volume compression chamber. Then, the large dead volume compression chambers are arranged so as to be continuous in the arrangement direction (corresponding to the rotation direction of the drive shaft) of the compression chambers. Further, also in the two groups, the value of the dead volume of each compression chamber is slightly changed (here, the same dead volume is included). At this time, it is preferable that the minimum dead volume in the group of large dead volume compression chambers is formed to be 2 to 7 times the maximum dead volume in the group of small dead volume compression chambers.

Therefore, in the two groups of the large dead volume compression chamber and the small dead volume compression chamber having a larger difference than the dead volume difference in each dead volume compression chamber, the volume and pressure in the compression chambers are increased. The transition curves of and are changed, and the torque fluctuation based on the compression reaction force generated in each compression chamber becomes different. Then, the n-th rotational component corresponding to the number of cylinders n obtained by the fast Fourier transform analysis of the sum of the torque fluctuations is reduced as compared with the case where the dead volume of each compression chamber is not changed.

By the way, the manufacturing error of each component constituting the compressor is different, and it is difficult to make the assembling tolerances the same for all products. On the other hand, in the reciprocating compressor configured as described above, the volume at the bottom dead center of the compression chamber having the minimum dead volume is between the maximum dead volume value and the minimum dead volume value. There is a difference corresponding to the range of 1% or more (hereinafter referred to as the reference suction volume) and 10% or less.
The amount of expansion of the dead volume sufficiently exceeds the amount of variation of the dead volume due to the assembling tolerance estimated from the processing accuracy of each part, and does not significantly reduce the compression efficiency of the compressor. For this reason, the change of the dead volume is ensured irrespective of the manufacturing error of each part, and a decrease in the compression performance of the compressor due to the change of the dead volume can be suppressed.

Further, in the double-headed piston type compressor constructed as described above, in addition to the above-mentioned change of dead volume, for the same double-headed piston, the dead volume on the front side and the dead volume on the rear side are the same. It is formed to have the same size as the dead volume. The phase of the compression reaction force in this double-headed piston type compressor has a difference of 180 ° between the total sum on the front side and the total sum on the rear side. Here, the rotation n-order component corresponding to the number n of the cylinders of the torque fluctuation that becomes the excitation force of the torsional vibration is an even-order component in the double-headed piston compressor. This even-order component is such that its phase repeats the same displacement an even number of times within a time corresponding to one rotation of the drive shaft. For this reason, the front-side total and the rear-side total of the rotation n-order component are superimposed in phase.

However, by changing the dead volume as described above, the sum of the n-th order component of the rotation on the front side and the sum of the rear side components are respectively reduced. And
The rotation n-order component of the entire compressor, on which the sum of the front side and the sum of the rear side are superimposed, is also reduced. Moreover, the rotation n
Even if the / 2nd-order component becomes an odd-order component, the odd-order component repeats the same displacement an odd number of times within a time corresponding to one rotation of the drive shaft, and the waveforms of the front and rear sides are mutually different. The state is reversed. For this reason, the rotational n / 2-order component cancels each other on the front side and the rear side of the same piston and disappears.

Moreover, in the double-headed piston type compressor constructed as described above, the dead volume of each compression chamber is set by changing the shape of the piston. Therefore, in setting the dead volume, the allowable range of the set value can be increased, and the change of the dead volume of each compression chamber can be ensured.

[0021]

An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the front side cylinder block 11 and the rear side cylinder block 12 are joined at a central portion. The valve plate 1 is provided on the front end surface of the cylinder block 11.
3, a front housing 15 is joined to the rear end surface of the cylinder block 12, and a rear housing 16 is joined to the rear end surface of the cylinder block 12 via a valve plate 14.

A suction valve 17a (1) is provided between the cylinder block 11 (12) and the valve plate 13 (14).
A suction valve forming plate 17 (18) forming 8a) is interposed. The discharge valve 19a is provided between the valve plate 13 (14) and the front (rear) housing 15 (16).
A discharge valve forming plate 19 (20) forming (20a) is interposed. The discharge valve 1 is provided between the discharge valve forming plate 19 (20) and the front (rear) housing 15 (16).
A retainer plate 21 (22) that regulates the maximum opening of 9a (20a) is interposed.

The cylinder blocks 11, 12, the front housing 15, the rear housing 16, the valve plates 13, 14, the suction valve forming plates 17, 18 and the discharge valve forming plates 19, 20 are fastened to each other by a plurality of through bolts 23. Fixed to form the compressor housing.

Discharge chambers 24 and 25 are formed on the outer circumferences of the front housing 15 and the rear housing 16, respectively.
Suction chambers 26 and 27 are formed on the center side. As shown in FIGS. 1 and 2, the cylinder block 11,
12 includes a plurality of cylinder bores 11a to 11e and 12a.
12e are formed so as to be parallel to each other, and a double-headed piston 28 is inserted inside them. Here, the compressor of this embodiment has five double-headed pistons 28.
And a 10-cylinder type reciprocating compressor.

The cylinder bores 11a to 11e, 12a
A pair of front and rear compression chambers 29 and 30 are defined and formed in the inside of 12e. The compression chambers 29 and 30 are provided in the valve plate
3, 14 into the suction chambers 26, 27 via the suction ports 13a, 14a, and likewise the valve plate 1
The discharge chambers 24 and 25 are communicated with each other through discharge ports 13b and 14b formed in the nozzles 3 and 14, respectively.

A crank chamber 31 is formed in the center of each of the cylinder blocks 11 and 12. A drive shaft 32 is rotatably supported in shaft holes 11f and 12f of both cylinder blocks 11 and 12 via a pair of radial bearings 33. The drive shaft 32 is rotated by an external drive source such as a vehicle engine via a clutch (not shown). A swash plate 34 as a cam plate is fitted and fixed to the intermediate outer peripheral portion of the drive shaft 32.
The double-headed piston 28 is attached to the shoe 3 on the swash plate 34.
The double-headed piston 28 is reciprocated in the cylinder bores 11a to 11e and 12a to 12e arranged so as to surround the drive shaft 32 by the rotation of the swash plate 34.

The boss portion 34a of the swash plate 34 is supported by thrust bearings 37, 38 on both front and rear wall surfaces of the cylinder blocks 11, 12 forming the crank chamber 31.

The crank chamber 31 is communicated with the suction chambers 26, 27 by suction passages 39, 40 formed in the cylinder blocks 11, 12. The crank chamber 31 is also connected to an external refrigerant circuit (not shown) via an intake flange (not shown) formed in the cylinder blocks 11 and 12. Further, the discharge chambers 24, 25 are connected to an external refrigerant circuit via discharge passages 41, 42 formed in the valve plates 13, 14 and the cylinder blocks 11, 12 and a discharge flange (not shown).

In this embodiment, the cylinder bores 11a to 11e and 12a to 12e have the same inner diameter. The front and rear heads of the two double-headed pistons 28 housed in the cylinder bores 11b, 11c, 12b, 12c are scraped off by a predetermined length. Therefore, when each piston 28 reaches the top dead center position, the head end surface of the piston 28 and the cylinder bores 11a to 11e, 12 are
The distance between the outer end surfaces of a to 12e is the cylinder bore 11
Within the arrangement plane of a to 11e and 12a to 12e (only 11a to 11e on the front side, only 12a to 12e on the rear side), there is a difference between the group in which the head of the viston 28 is removed and the group in which it is not removed. This allows
The dead volume in each compression chamber 29, 30 is set to two different values, large and small. Here, the dead volume is the volume of the compression chambers 29 and 30 when the piston 28 reaches the top dead center position.

Here, the dead volume of each compression chamber 30 on the rear side will be described. As shown in FIGS.
The cylinder bores 12a, 12d, 12e accommodate double-headed pistons 28 whose heads are not scraped off, so that the dead volume of the compression chamber 30 is reduced. That is, in the cylinder bores 12a, 12d, and 12e, the small dead volume compression chamber 30a (other compression chamber) in which the dead volume value is set small is formed. Further, the cylinder bores 12b and 12c accommodate the double-headed piston 28 whose head is scraped off, and the dead volume of the compression chamber 30 is large. That is, the cylinder bores 12b and 12c are formed with a large dead volume compression chamber 30b in which the value of the dead volume is set large. Then, the compression chambers 30 in the cylinder bores 12a to 12e are divided into a group of large dead volume compression chambers 30b and a group of small dead volume compression chambers 30a. Also, the cylinder bores 12b, 12c
The large dead volume compression chamber 30b is arranged so as to be continuous in the arrangement direction of the compression chambers 30.

Further, the large dead volume compression chamber 30
The difference between the dead volume value of b and the dead volume value of the small dead volume compression chamber 30a is set to be larger than the difference of the dead volume value in each group. In this embodiment, there is no difference between the dead volumes of the large dead volume compression chamber 30b, and similarly there is no difference between the dead volumes of the small dead volume compression chamber 30a. Then, the minimum dead volume (both the same) in the group of the large dead volume compression chamber 30b is the same as the small dead volume compression chamber 30b.
2 to 7 of the maximum dead volume of a (all three are the same)
Times, preferably 2.5 to 6 times, more preferably 3 to 6 times.
It is set to be 5.5 times.

Further, between the values of the maximum dead volume and the value of the minimum dead volume between the compression chambers 30, the volume at the bottom dead center of the compression chamber 30 having the minimum dead volume (hereinafter referred to as the reference suction volume). It is set so that there is a corresponding difference within the range of 1% or more and 10% or less with reference to (volume). This set value is 3
The range is preferably from 7% to 7%, and more preferably from 3.5% to 5.5%. In the compressor of this embodiment, the reference suction volume is, for example, 20 cc, and the dead volume in the large dead volume compression chamber 30b is 0.8 cc as compared with the small dead volume compression chamber 30a.
It has been expanded. This dead volume change amount corresponds to 4% of the reference suction volume.

Moreover, the double-headed piston 28 is formed so that the front side and the rear side thereof have the same scraping amount. Therefore, for one double-headed piston 28, the dead volume of the compression chamber 29 on the front side and the dead volume of the compression chamber 30 on the rear side have the same size. In other words, double-headed piston 28
The compression chamber 29 in the cylinder bore 11a and the compression chamber 30 in the cylinder bore 12a, which are opposed to each other in the axial direction of the drive shaft 32 via, are set so as to have the same dead volume. Similarly, the cylinder bore 11
b and 12b, 11c and 12c, 11d and 12d, 11e
And 12e, the dead volumes of the compression chamber 29 and the compression chamber 30 are the same. Therefore, the large dead volume compression chamber 2 on the front side
The arrangement of 9b and the small dead volume compression chamber 29a is the same as the arrangement of the large dead volume compression chamber 30b and the small dead volume compression chamber 30a on the rear side in the rotation direction of the drive shaft 32.

Next, the operation of the reciprocating compressor constructed as described above will be described. When the drive shaft 32 is rotated by an external drive source such as a vehicle engine, the swash plate 34 in the crank chamber 31 is rotated, and the plurality of double-headed pistons 28 are connected to the cylinder bores 11 a to 11 via the shoes 35 and 36.
e, reciprocating within 12a-12e. Due to the movement of the double-headed piston 28, the refrigerant gas introduced from the external refrigerant circuit (not shown) into the crank chamber 31 via the suction flange is
From the crank chamber 31 through the suction passages 39 and 40, the suction chamber 2
Guided to 6, 27. In the re-expansion / suction stroke in which the double-headed piston 28 moves from top dead center to bottom dead center, the compression chamber 2
The suction valves 17a and 18a are opened as the pressure in the suction ports 9 and 30 decreases, and the refrigerant gas in the suction chambers 26 and 27 is discharged into the suction port 1
It is sucked into the compression chambers 29, 30 through 3a, 14a.

Next, in the compression / discharge stroke in which the double-headed piston 28 moves from the bottom dead center to the top dead center, the compression chambers 29, 3
The refrigerant gas in 0 is compressed. When the refrigerant gas reaches a predetermined pressure, the high pressure compressed refrigerant gas is discharged into the discharge valve 19
A is discharged to the discharge chambers 24 and 25 through the discharge ports 13b and 14b. Furthermore, the discharge chamber 2
The compressed refrigerant gas in Nos. 4 and 25 is supplied to the condenser, the expansion valve, and the evaporator forming the external refrigerant circuit through the discharge passages 41 and 42 and the discharge flange (not shown), and is used for air conditioning in the vehicle compartment.

As shown in FIG. 9, in a 10-cylinder double-headed piston type compressor having a uniform dead volume, the phase of the compression reaction force of each compression chamber is the sum of the front side and the sum of the rear side. It will be 180 ° off. Here, the rotation tenth-order component as the rotation nth-order component obtained by the fast Fourier transform analysis of the sum of the compression reaction forces of the compression chambers has the same displacement ten times, that is, an even number of times in one rotation of the drive shaft 32. It has a regular waveform that repeats. For this reason, the phase of the sum of the rotation 10th-order component on the front side and the phase of the sum of the rotation-side 10th components on the rear side match, and the rotation 10th-order component of the torque fluctuation derived from the compression reaction force of each compression chamber is completely superposed. It is the main component of the exciting force of torsional vibration between the drive shaft 32 and a clutch (not shown).

In this case, the rotational fifth-order component as the rotational n / 2nd-order component is such that the same displacement is repeated five times, that is, an odd number of times, during one rotation of the drive shaft 32. The fifth order component of rotation has a 180 ° phase shift between the sum on the front side and the sum on the rear side, and cancels each other.

Here, when the dead volume is made different between the front side and the rear side of the double-headed piston 28 in order to reduce the rotational tenth-order component, as shown in FIG. , The front-side total and the rear-side total are deviated from each other to reduce the phase. However, the phase difference between the front side and the rear side of the fifth-order rotational component also occurs in the same manner as the tenth-order rotational component, and a new overlapping portion is generated.
For this reason, the rotation fifth-order component of the torque fluctuation may become a new noise generation factor.

On the other hand, in the compressor of this embodiment, the compression chambers 29, 3 are provided on the front side and the rear side.
The dead volume value of 0 has been changed so as to form two groups. The large dead volume compression chambers 29b and 30b are arranged so as to be continuous in the arrangement direction of the compression chambers 29 and 30. These compression chambers 29, 3
With the change of the dead volume of 0, the curves of the changes in the volumes and the pressures of the compression chambers 29, 30 become different from each other. That is, as shown in FIG. 4, there is a difference in the timing of pressure change in the compression chambers 29 and 30 between the one having a small dead volume and the one having a large dead volume in the re-expansion process and the compression process. In addition, there is a difference in pressure during overcompression in the compression stroke.

As a result, as shown in FIG. 5, the peak position of the torque is shown in the transition curve of the compression torque per compression chamber 29, 30 between the one with a small dead volume and the one with a large dead volume. Difference occurs. Therefore, as shown in FIG. 6, in the compression torque of the entire compressor in which the compression torques of the ten compression chambers 29 and 30 are superposed, the dead volume is changed as compared with the case where the dead volume is not changed. In addition, the regularity of the curve of the torque fluctuation is lost, and the overall level decreases. Therefore, as shown in FIG. 7, the rotational tenth-order component of the torque fluctuation corresponding to the number of cylinders obtained by the fast Fourier transform analysis of the sum of the compression reaction forces is reduced.

By the way, in general, the manufacturing error of each component constituting the compressor is different, and it is difficult to make the same assembly tolerance in all products. The amount of variation of the dead volume due to the assembly tolerance is less than 1% of the reference suction volume, even if the maximum is estimated from the processing accuracy of each part. On the other hand, in the compressor of this embodiment, a difference corresponding to 4% of the reference suction volume exists between the maximum dead volume value and the minimum dead volume value. For this reason, the change of the dead volume is ensured even in consideration of the assembly tolerance. In addition, such an increase in the dead volume does not extremely reduce the compression efficiency of the compressor.

Further, the dead volume of the front-side compression chamber 29 and the rear-side compression chamber 30 of one double-headed piston 28 is formed to be the same. For this reason, the fifth-order rotational component cancels each other out while maintaining a 180 ° phase shift between the front-side total and the rear-side total.

According to this embodiment configured as described above, the following excellent effects are exhibited. (A) On the front side and the rear side, the values of the dead volumes of the compression chambers 29 and 30 are changed so as to be roughly divided into two groups. The large dead volume compression chambers 29b and 30b are compressed into the compression chambers 29 and 3.
They are arranged so as to be continuous in the arrangement direction of 0. As a result, in the 10-cylinder type double-headed piston type compressor, the 10th-order rotational component, which is the main component of the torque fluctuation that becomes the exciting force of the torsional vibration, is reduced. Accordingly, due to the torsional vibration, the generation of noise due to the resonance phenomenon of the compressor and the auxiliary equipment connected thereto is reduced, and the noise level in the vehicle compartment is reduced.

(B) Large dead volume compression chamber 29
The difference between the dead volume values of b and 30b and the dead volume values of the small dead volume compression chambers 29a and 30a is set to be larger than the difference of the dead volume values within the group of the dead volume compression chambers. ing. And a large dead volume compression chamber 29b,
The dead volume of 30b is formed to be 2 to 7 times, preferably 2.5 to 6 times, and more preferably 3 to 5.5 times the dead volume of the small dead volume compression chambers 29a and 30a. Further, the difference between the maximum dead volume value and the minimum dead volume value is the small dead volume compression chamber 29 having the minimum dead volume.
It is formed so as to correspond to 4% of the reference suction volume in a and 30a. Therefore, in the compressor of this embodiment, the dead volume of each compression chamber 29, 30 can be changed even if the assembly tolerance is taken into consideration, and the compression performance of the compressor is not deteriorated due to the change of the dead volume. Can be suppressed.

(C) The front side compression chamber 29 and the rear side compression chamber 30 of one double-headed piston 28 are formed to have the same dead volume. For this reason, the fifth order component of rotation disappears because the total sum on the front side and the total sum on the rear side cancel each other. Therefore, in combination with the effects of the above items (a) and (b), the generation of the fifth-order rotation component can be suppressed while reducing the tenth-order rotation component of the torque fluctuation.

(D) Large dead volume compression chamber 29
The dead volumes b and 30b are set by cutting off both end surfaces of the double-headed piston 28. Therefore, in setting the dead volume, the allowable range of the set value can be increased, and the compression chambers 29, 3
The change of the dead volume of 0 can be easily secured.

The present invention can be modified and embodied as follows. (1) The dead volume of each compression chamber 29, 30 is changed by providing a recess in the head of the double-headed piston 28.

(2) The dead volume of each compression chamber 29, 30 is changed by providing a groove on the head of the double-headed piston 28. (3) The dead volume of each compression chamber 29, 30 is changed by providing a cutout portion on the inner peripheral surface of each of the cylinder bores 11a to 11e, 12a to 12e.

(4) The cylinder bores 11a to 11e, 12a are changed by changing the dead volumes of the compression chambers 29, 30.
Change the length of ~ 12e respectively. (5) Changing the dead volume of each compression chamber 29, 30 by changing the plate thickness of the valve plates 13, 14.

(6) The dead volume of each compression chamber 29, 30 is changed by changing the plate thickness of the suction valves 17a, 18a. Even with the above configurations (1) to (6), the dead volume of each compression chamber 29, 30 can be changed with a simple configuration.

(7) The present invention may be embodied in a double-headed piston compressor having a number of cylinders other than those described in the above embodiment, for example, 6, 8 and 12 cylinders. (8) Large dead volume and small dead volume compression chambers 29a, 29 on the front and rear sides, respectively.
The values of the dead volumes b, 30a, and 30b are changed to a plurality of types, or different values are formed. The change of the dead volume may be arbitrarily set or may be automatically set by the manufacturing tolerance of the piston 28 and other parts.

(9) The difference between the minimum value and the maximum value of the dead volume is set to 1 with the lower limit of 1% of the reference suction volume.
Change to 0% as the upper limit. (10) The reference suction volume is set to a value other than those described in the above embodiments.

Even if the above configurations (7) to (10) are adopted, the rotation n / 2nd order component corresponding to the number of cylinders n is reduced while the rotation n / 2nd order component is an odd order component. Can be suppressed.

(11) Two or more types of dead volumes should be changed in only one of the front compression chambers 29 or the rear compression chambers 30. (12) The present invention is embodied in a single-head piston type compressor.

Even with the above configurations (11) and (12), the n-th order rotation component corresponding to the number of cylinders n can be reduced. (13) The present invention is embodied in a wave cam plate type reciprocating compressor.

(14) Cylinder bores 11a to 11e,
At least two of the compression chambers within the arrangement plane of 12a to 12e should form a group of small dead volume compression chambers 29a, 30a.

According to this structure, the transition of the volume and pressure of the compression chamber can be skillfully changed, and the torque fluctuation which is the exciting force of the torsional vibration can be reduced.

[0058]

As described above in detail, the present invention has the following excellent effects. The dead volumes of the respective compression chambers in the arrangement plane of the cylinder bores are changed so as to form two large groups. The large dead volume compression chambers are arranged so as to be continuous in the arrangement direction of the compression chambers. Therefore, the rotational nth order component of the torque fluctuation corresponding to the number of cylinders n is greatly reduced, and the drive shaft-
Excitation force of torsional vibration of the clutch system is suppressed. And, in the compressor and the auxiliary machine connected thereto, the resonance phenomenon excited by the torsional vibration is reduced,
The noise level in the passenger compartment can be reduced.

The value of the minimum dead volume in the group of large dead volume compression chambers is 2 to 7 times the value of the maximum dead volume in the group of small dead volume compression chambers. In addition, there is a difference between the maximum dead volume value and the minimum dead volume value of each compression chamber within the range of 1% or more and 10% or less with respect to the reference suction volume. Therefore, the change of the dead volume can be ensured even in consideration of the assembly tolerance.

Further, in the double-headed piston type compressor, the dead volume on the front side and the dead volume on the rear side are configured to have the same size for one piston. For this reason, the rotational n / 2-order component when the number of cylinders is n cancels each other out on the front side and the rear side of one piston and disappears. Therefore, in combination with the effect of the invention described above, it is possible to suppress the generation of the rotation n / 2-order component while reducing the rotation n-order component corresponding to the number of cylinders n. Then, the occurrence of a new vibration generation factor due to the countermeasure for the rotation n-order component is prevented.

Moreover, the dead volume of the large dead volume compression chamber is set by changing the shape of the piston. Therefore, in setting the dead volume, the allowable range of the set value can be increased, and the change of the dead volume of each compression chamber can be ensured.

[Brief description of drawings]

FIG. 1 is a sectional view showing a compressor of an embodiment of the present invention.

2A is a line 2a-2a, and FIG. 2B is a line 2b.
2b is a cross-sectional view taken along line 2b.

FIG. 3A is an explanatory diagram related to changing a dead volume of each compression chamber on a front side and a rear side in FIG.

FIG. 4 is an explanatory diagram showing a relationship between a shaft rotation angle and a bore pressure.

FIG. 5 is an explanatory diagram showing a relationship between a shaft rotation angle and a compression torque per compression chamber.

FIG. 6 is an explanatory diagram showing a relationship between a shaft rotation angle and a compression torque of the entire compressor in which 10 compression chambers are superposed.

FIG. 7 is an explanatory diagram regarding an order component of compression torque.

FIG. 8 is an explanatory diagram showing a reduction of a rotation tenth-order component and a change of a rotation fifth-order component.

9A is a rotation fifth-order component, and FIG. 9B is a rotation 10th component.
Explanatory drawing regarding the superposition phenomenon of the sum total of the front side of the following component, and the sum total of the rear side.

[Explanation of symbols]

11, 12 ... Cylinder block forming part of housing, 11a to 11e, 12a to 12e ... Cylinder bore, 15 ... Front housing forming part of housing, 16 ... Rear housing forming part of housing, 28 ... Double-headed piston, 29, 30 ... Compression chamber, 29
a, 30a ... Small dead volume compression chamber, 29b, 30
b ... Large dead volume compression chamber, 31 ... Crank chamber, 3
2 ... drive shaft, 34 ... swash plate as cam plate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Nakamoto 2-chome, Toyota-cho, Kariya city, Aichi Prefecture Toyota Industries Corporation

Claims (8)

[Claims] 1. A drive shaft is supported inside a housing, a crank chamber is formed, and a plurality of cylinder bores are arranged in a cylinder block forming a part of the housing so as to surround the drive shaft. A piston is reciprocally housed therein to define a compression chamber, a cam plate is integrally rotatably attached to the drive shaft, and the piston is reciprocally moved in conjunction with the rotation of the cam plate, In a reciprocating compressor that compresses refrigerant gas, each of the compression chambers has a predetermined dead volume, and at least two of the compression chambers in the array surface of the cylinder bores are in the same array surface. In addition to forming a group of large dead volume compression chambers in which the value of the dead volume is set to be larger than that of the other compression chambers, Configured as a group of small dead volume compression chamber,
The difference between the dead volume value of the large dead volume compression chamber and the dead volume value of the small dead volume compression chamber is set to be larger than the difference of the dead volume values within each dead volume compression chamber group, and A reciprocating compressor, wherein the dead volume compression chambers are arranged so as to be continuous in the arrangement direction of the cylinder bores. 2. The value of the minimum dead volume in the group of the large dead volume compression chambers is set to be 2 to 7 times the value of the maximum dead volume in the group of the small dead volume compression chambers. The reciprocating compressor according to claim 1, wherein the compressor is a reciprocating compressor. 3. The maximum dead volume value and the minimum dead volume value between the compression chambers have a difference of 1% or more of the volume at the bottom dead center of the compression chamber having the minimum dead volume. The reciprocating compressor according to claim 1 or 2. 4. The maximum dead volume value and the minimum dead volume value between the compression chambers have a difference of not more than 10% of the volume at the bottom dead center of the compression chamber having the minimum dead volume. Claim 1 characterized by the above-mentioned.
The reciprocating compressor according to any one of 3 to 3. 5. The reciprocating compressor according to claim 1, wherein dead volumes in the groups of the large dead volume compression chambers are different from each other. 6. The cylinder bores are formed so as to face each other in the front-rear direction, the piston is configured as a double-headed type, and predetermined dead volumes are formed in the compression chambers on the front and rear sides, respectively. The reciprocating compressor according to any one of 5 above. 7. The reciprocating compressor according to claim 6, wherein a dead volume on the front side and a dead volume on the rear side are formed to have the same size with respect to one double-headed piston. 8. The reciprocating compressor according to claim 1, wherein the dead volume of each compression chamber is formed by changing the shape of the piston.