JPH09222079A - Reciprocation type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reciprocation type compressor to reduce the generation of noise and vibration through reduction of a rotation n-th component of a torque fluctuation corresponding to the number of cylinder. SOLUTION: Cylinder bores 33-1-33-5 are formed facing a pair of cylinder blocks and a double end cylinder is contained in the cylinder bores 33-1-33-5 to partition a compression chamber. By shaving off the head part of the double end piston by a given length, the dead volume of the compression chamber in each of the cylinder bores 33-1-33-5 is varied. The dead volumes of the compression chambers on both sides of one double end piston are set to the same as each other. At least one of suction valves 29a-1-29a-5 and delivery valves 31a-1-31a-5 are formed such that rigidity is increased with the increase of the dead volume of the compression chamber.

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 accommodated in the cylinder bore so as to be capable of reciprocating, and a compression chamber is defined between the piston and the opposing valve structure. An intake valve and a discharge valve for opening and closing the compression chamber are provided on the valve structure. A swash plate is integrally rotatably mounted on the drive shaft, and the piston is reciprocated in association with the rotation of the swash plate to compress the refrigerant gas in the compression chamber.

[0003]

During the compression operation of this conventional compressor, a compression reaction force acts on each piston in association 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. Of these frequency components, the main component is the n-th rotation component corresponding to the number of cylinders n. 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 the above-mentioned problems, the applicant of the present invention has disclosed, in Japanese Utility Model Laid-Open No. 1-91084, a discharge reed valve corresponding to a compression chamber in each cylinder bore so that the valve opening pressure is different. The proposed configuration is proposed. The valve opening pressure of these discharge reed valves is changed by changing the plate thickness of each discharge reed valve. In this way, by changing the valve opening pressure of each discharge reed valve, the transition curve of the pressure in each compression chamber is changed, and the peak of the specific frequency occurring in the vibration level is reduced. In the present invention, the configuration is further optimized in order to further improve the noise and vibration suppression effect of the configuration.

An object of the present invention is to provide a reciprocating compressor, which is an exciting force of torsional vibration, in which a rotational nth order component of torque fluctuation corresponding to the number of cylinders n is reduced, and which causes less noise and vibration. To do.

[0006]

In order to achieve the above object, according to the invention as set forth in claim 1, a piston is reciprocably housed in a cylinder bore, and the piston is disposed between the piston and a valve assembly opposed thereto. In a reciprocating compressor in which a compression chamber is divided and formed, and a suction valve and a discharge valve for opening and closing the compression chamber are provided on the valve structure, each compression chamber has a predetermined dead volume. That is, at least one of the intake valve and the discharge valve is formed such that the greater the dead volume of the corresponding compression chamber, the greater the rigidity.

According to a second aspect of the present invention, in the reciprocating compressor according to the first aspect, the suction valve and the discharge valve have different rigidity by changing the plate thickness. According to a third aspect of the invention, in the reciprocating compressor according to the first or second aspect, the suction valve and the discharge valve have an opening / closing portion and a neck portion, and the rigidity is obtained by changing the width of the neck portion. Is a change.

In the invention according to claim 4, a piston is reciprocally housed in the cylinder bore to define a compression chamber between the piston and a valve assembly facing the piston, and the compression chamber is formed on the valve assembly. In a reciprocating compressor in which a suction valve and a discharge valve for opening and closing the compression chamber are provided sandwiching a valve plate, each compression chamber has a predetermined dead volume, and the suction valve and the discharge valve At least one of the valve and the valve is formed such that the larger the dead volume of the corresponding compression chamber, the larger the contact area with the valve plate.

According to the fifth aspect of the present invention, the first to fourth aspects are provided.
In the reciprocating compressor according to any one of items 1 to 3, the maximum dead volume value and the minimum dead volume value between the compression chambers are 1% of the volume at the bottom dead center of the compression chamber having the minimum dead volume. The above difference is added.

In the invention described in claim 6, claims 1 to 5 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 arrangement of the dead volumes of the front-side compression chambers and the sizes of the dead volumes of the rear-side compression chambers are large and small. Are arranged so that they are the same in the rotational direction of the drive shaft.

According to an eighth aspect of the invention, in the reciprocating compressor according to the sixth or seventh aspect, the dead volume on the front side and the dead volume on the rear side have the same size for one piston. It was formed.

Therefore, in the reciprocating compressor configured as described above, the value of the dead volume (the volume of the compression chamber when the piston reaches the top dead center) is changed by each compression chamber (the same dead volume). The values of these dead volumes are set within the range of at least two types and n types or less (n is the number of compression chambers). For this reason, the compression chamber having the larger dead volume causes a delay in the transition curves of the volume and the pressure in the compression stroke and the re-expansion stroke. Then, the transition curve in each compression chamber is changed so that the torque fluctuation based on the compression reaction force generated in each compression chamber becomes different.

Further, at least one of the intake valve and the discharge valve corresponding to each compression chamber is changed in rigidity or contact area with the valve plate. Therefore, when the valve stiffness is changed, the valve opening timing is delayed as the valve stiffness is increased. Further, when the contact area with the valve plate is changed, the adhesion force between the valve and the valve plate based on the surface tension of the lubricating oil interposed between the valve and the valve plate is changed. The larger the contact area, the later the valve opening timing. That is, the element that determines the valve opening pressure of at least one of the intake valve and the discharge valve corresponding to each compression chamber is changed, and the opening timing of the intake valve and the discharge valve in each compression chamber is deviated. Also by this, the transition curve of the volume and pressure in each compression chamber is changed, and the torque fluctuation based on the compression reaction force generated in each compression chamber becomes different.

Then, the superposed portion of the torque fluctuation based on the compression reaction force generated in each compression chamber is reduced, and the n-th order rotation component corresponding to the number of cylinders n obtained by the fast Fourier transform analysis of the sum of the torque fluctuation is obtained. Will be reduced. Moreover, the intake valve and the discharge valve having a correspondingly larger dead volume of the compression chamber are formed so that at least one of the rigidity and the contact area with the valve plate is larger. For this reason, the change of the transition curve due to the increase of the dead volume and the change of the transition curve due to the change of the valve rigidity and the contact area with the valve plate act synergistically to make the rotation n-order component more effective. Will be reduced.

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. Here, the value between the maximum dead volume value and the minimum dead volume value corresponds to 1% or more of the volume at the bottom dead center of the compression chamber having the minimum dead volume (hereinafter referred to as the reference suction volume). There is a difference. The amount of expansion of the dead volume is sufficiently larger than the variation of the dead volume due to the assembly tolerance estimated to the maximum from the machining accuracy of each part. Therefore, the change of the dead volume is ensured regardless of the manufacturing error of each component.

Further, in the double-headed piston type compressor constructed as described above, in addition to the change of the dead volume as described above, 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 rotational n-th order component corresponding to the number of cylinders n of the torque fluctuation, which is the exciting force of the torsional vibration, becomes an even-order component in the double-headed piston type 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. Therefore, the rotation n
The sum of the next component on the front side and the sum of the rear components on the rear side are superposed in phase with each other.

However, by changing the dead volume of each compression chamber as described above and changing at least one of the rigidity and the contact area with the valve plate in the intake valve and the discharge valve corresponding to each compression chamber, The sum of the n-th order component of the rotation on the front side and the sum of the components on the rear side are reduced. Then, the rotational n-th order component of the entire compressor in which the front side total and the rear side total are superimposed is also reduced. Moreover, even if the rotational n / 2-order component becomes an odd-order component, the odd-order component repeats the same displacement an odd number of times within the time corresponding to one rotation of the drive shaft, and the front side and the rear side. The waveforms are in a mutually inverted state. 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.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS.

As shown in FIGS. 1 and 2, a front cylinder block 21 and a rear cylinder block 22.
And are joined at the central portion. A front housing 25 is joined to the front end surface of the cylinder block 21 via a valve assembly 23, and a rear housing 26 is joined to the rear end surface of the cylinder block 22 via a valve assembly 24. There is. The cylinder blocks 21 and 22, the front housing 25, the rear housing 26, and the valve components 23 and 24 are clamped and fixed to each other by a plurality of through bolts 27, and these form a compressor housing.

Each of the valve components 23 and 24 includes a suction valve forming plate 29, a valve plate 30, and a discharge valve forming plate 31.
And a gasket 32 that also serves as a retainer plate are sequentially joined. 5 for each valve plate 30
The individual suction ports 30a and the discharge ports 30b are formed at predetermined intervals. The intake valve forming plate 29 has five intake valves 29a-1, 29a-2, 29a- so as to open and close each intake port 30a of the valve plate 30.
3, 29a-4 and 29a-5 are formed. Each of the suction valves 29a-1 to 29a-5 is formed with an opening / closing portion 29b facing the suction port 30a and a neck portion 29c continuous with the opening / closing portion 29b.

The discharge valve forming plate 31 includes five discharge valves 31a-1, 31a-2, 31a-3, 31a-4, 31 so as to open and close each discharge port 30b of the valve plate 30.
a-5 are formed. These discharge valves 31a-1 to 31a
-5 includes an opening / closing part 31b facing each discharge port 30b.
And a neck portion 31c continuous with the opening / closing portion 31b. The gasket 32, which also serves as a retainer plate, is formed with five retainers 32a so as to regulate the maximum opening of each of the discharge valves 31a-1 to 31a-5.

A plurality of cylinder bores 33-1, 33-2, 33-3, 33-4, 3 are provided in the cylinder blocks 21, 22.
3-5 are formed so as to be parallel to each other. A double-headed piston 34 is reciprocally housed inside each of the cylinder bores 33-1 to 33-5. Both ends of the piston 34 and the valve components 23, 24 facing the piston 34
And a pair of front and rear compression chambers 35 and 36 are formed in each of the cylinder bores 33-1 to 33-5. In addition,
The compressor of this embodiment is a 10-cylinder type reciprocating compressor including five double-headed pistons 34.

An annular partition wall 37 is formed in the front housing 25 and the rear housing 26, and suction walls 38, 39 are defined by the partition wall 37 on the outer peripheral side in each of the housings 25, 26. The discharge chambers 40 and 41 are defined on the center side. The suction chambers 38, 39 are in communication with the compression chambers 35, 36 via the suction port 30a formed in the valve plate 30 of the valve assembly 23, 24. In addition, each discharge chamber 40,
Reference numeral 41 communicates with the compression chambers 35, 36 via the discharge port 30b formed in the valve plate 30 of the valve assembly 23, 24.

A crank chamber 42 is formed in the center of each of the cylinder blocks 21 and 22. A drive shaft 43 is rotatably supported in the shaft holes 21a and 22a of both cylinder blocks 21 and 22 via a radial bearing 44. The drive shaft 43 is rotated by an external drive source such as a vehicle engine via a clutch (not shown).

At the intermediate outer peripheral portion of the drive shaft 43,
A swash plate 45 as a cam plate is fitted and fixed. On the swash plate 45, the double-headed piston 34 is provided with a pair of shoes 46.
The two-headed piston 34 is reciprocated in the cylinder bores 33-1 to 33-5 by the rotation of the swash plate 45.
The boss portion 45 a of the swash plate 45 is supported by the thrust bearing 47 on both front and rear wall surfaces of the cylinder blocks 21 and 22 forming the crank chamber 42.

The crank chamber 42 is communicated with the suction chambers 38, 39 via suction passages 48 formed in the cylinder blocks 21, 22 and the valve components 23, 24. The crank chamber 42 is connected to an external refrigerant circuit via a suction flange (not shown) formed in the cylinder blocks 21 and 22. Further, the discharge chambers 40, 41 are connected to an external refrigerant circuit via a discharge passage 49 formed in the cylinder blocks 21, 22 and the valve structures 23, 24 and a discharge flange (not shown) formed in the cylinder blocks 21, 22. It is connected.

As shown in FIGS. 1 and 3, each of the cylinder bores 33-1 to 33-5 is formed to have the same inner diameter. Then, each cylinder bore 33-1 to
The heads on the front and rear sides of the double-headed piston 34 housed in 33-5 are each scraped off by a predetermined length. In addition, the amount of scraping is the cylinder bore 3
The pistons 34 in 3-1 and 33-3 are set to the minimum, the piston 34 in the cylinder bore 33-5 is set to the middle, and the pistons 34 in the cylinder bores 33-2 and 33-4 are set to the maximum so that there are three types. Has been done.

Therefore, when each piston 34 reaches the top dead center position, the head end surface of the piston 34 and the valve assembly 23,
The distances to 24 are different from each other. As a result, the dead volumes in the compression chambers 35 and 36 are set to different values. The dead volume is the volume of the compression chambers 35 and 36 when the piston 34 reaches the top dead center position.

Here, the dead volume of each compression chamber 36 on the rear side will be described in detail. As shown in FIG.
Regarding the cylinder bores 33-1 and 33-3, the double-headed piston 34 whose head is not scraped off is accommodated, and the dead volume is minimized. Further, the cylinder bore 33-5 accommodates the double-headed piston 34 whose head is scraped off by a predetermined amount, and has a dead volume in the middle. Further, the cylinder bores 33-2 and 3
Regarding No. 3-4, the double-headed piston 34 whose head is scraped off further is accommodated, and the dead volume is maximized. In this way, the dead volume in the compression chamber 36 is enlarged by increasing the scraping amount of the head of the piston 34.

Further, the expansion amount of each dead volume is determined by the cylinder bores 33-1 and 3 having the minimum dead volume.
The volume of the compression chamber 36 at the bottom dead center of 3-3 (hereinafter referred to as a reference suction volume) is set as a reference. In the compressor of this embodiment, the reference suction volume is, for example, 20c.
As c, the dead volume of each compression chamber 36 is expanded by 0.4 cc in the cylinder bore 33-5 and further expanded by 0.4 cc in the cylinder bores 33-2 and 33-4. That is, in the cylinder bores 31-2 and 33-4 set to the maximum dead volume, the cylinder bore 33-1 set to the minimum dead volume is used.
The dead volume is increased by 0.8 cc as compared with 33 and 33-3.

Further, the double-headed pistons 34 are formed so that the front side and the rear side thereof have the same scraping amount. Therefore, one double-headed piston 34
On the other hand, the dead volume of the compression chamber 35 on the front side and the dead volume of the compression chamber 36 on the rear side have the same size. In other words, double-ended piston 3
4, the compression chamber 35 inside the front cylinder bore 33-1 and the compression chamber 36 inside the rear cylinder bore 33-1 that face each other in the axial direction of the drive shaft 43 are set to the same dead volume. ing.

Similarly, the cylinder bores 33-2, 33-3, 3
Also for 3-4 and 33-5, the dead volumes of the compression chamber 35 and the compression chamber 36 are the same on the front side and the rear side, respectively. Therefore, the size of the dead volume of each compression chamber 35 on the front side and the size of the dead volume of each compression chamber 36 on the rear side are formed to be the same in the rotation direction of the drive shaft 43. I have. As described above, in the compressor of this embodiment, three types of dead volumes are formed.

Further, as shown in FIGS. 2 to 6, suction valves 29a-1 to 29a-5 and discharge valves 31a-1 to corresponding to the compression chambers 35 and 36 of the cylinder bores 33-1 to 33-5, respectively. 31
The a-5 is formed so that its rigidity (a factor that determines the valve opening pressure) changes according to the size of the dead volume in the compression chambers 35 and 36. In this case, the suction valves 29a-1 to 29a-5 and the discharge valve 31a-1 corresponding to the compression chambers 35 and 36 of the cylinder bores 33-1 to 33-5 having a large dead volume.
It is set so that the rigidity is increased as it goes up to 31a-5.

That is, the intake valves 29a-1 and 29a-3 corresponding to the cylinder bores 33-1 and 33-3 having the minimum dead volume have a single structure and have a thin plate thickness and a narrow neck portion 29c. , Is formed to have a small rigidity. The intake valve 29a-5 corresponding to the intermediate dead volume cylinder bore 33-5 is formed to have intermediate rigidity by reducing the plate thickness with a single structure and widening the neck portion 29c. . Cylinder bores 33-2 and 3 with maximum dead volume
The suction valves 29a-2 and 29a-4 corresponding to No. 3-4 have a double structure and are formed to have a large rigidity by thickening the plate thickness and widening the width of the neck portion 29c.

Similarly, the discharge valves 31a-1 and 3 corresponding to the cylinder bores 33-1 and 33-3 having the minimum dead volume are provided.
1a-3 is a single structure with a thin plate thickness, and a neck 3
By narrowing the width of 1c, it is formed so as to have a small rigidity. The discharge valve 31a-5 corresponding to the intermediate dead volume cylinder bore 33-5 is formed to have intermediate rigidity by reducing the plate thickness with a single structure and widening the neck portion 31c. .
Cylinder bores 33-2 and 33-4 with maximum dead volume
The discharge valves 31a-2 and 31a-4 corresponding to 2 are formed to have great rigidity by increasing the plate thickness in a double structure and widening the neck 31c.

As described above, with respect to the intake valves 29a-1 to 29a-5, the cylinder bore 33 having a large dead volume is used.
-1 to 33-5 are formed to have higher rigidity. Therefore, in the re-expansion / suction stroke of the compressor, the suction valves 29a-1 to 29-5a having high rigidity are
The valve will be opened later. Also, the discharge valve 31a
-1 to 31a-5 are also formed such that the ones corresponding to the cylinder bores 33-1 to 33-5 having a large dead volume have higher rigidity. Therefore, in the compression / discharge stroke of the compressor, the discharge valve 31a having high rigidity is used.
The valve will be opened with a delay of -1 to 31a-5.

Next, the operation of the reciprocating compressor having the above structure will be described. When the drive shaft 43 is rotated by an external drive source such as a vehicle engine (not shown), the swash plate 45 in the crank chamber 42 is rotated, and the plurality of double-headed pistons 34 are connected to the cylinder bore 3 via the shoes 46.
It is reciprocated within 3-1 to 33-5. This double-headed piston 34
Due to the above movement, the refrigerant gas introduced from the external refrigerant circuit (not shown) to the crank chamber 42 via the intake flange (not shown) is also introduced from the crank chamber 42 to the intake chambers 38 and 39 via the intake passage 48. During the re-expansion / suction stroke in which the double-headed piston 34 moves from the top dead center to the bottom dead center, the pressure in the compression chambers 35 and 36 decreases and the suction valves 29a-1 to 29a-2.
9a-5 is opened, and the refrigerant gas in the suction chambers 38 and 39 is
It is sucked into the compression chambers 35 and 36 through the suction port 30a.

Next, in the compression / discharge stroke of the double-headed piston 34 from bottom dead center to top dead center, the compression chambers 35, 36 are
The refrigerant gas inside is compressed. When the refrigerant gas reaches a predetermined pressure, the high pressure compressed refrigerant gas is discharged into the discharge valve 31a-1.
~ 31a-5 are pushed away and discharged into the discharge chambers 40, 41 through the discharge port 30b. Furthermore, the discharge chambers 40, 4
The compressed refrigerant gas in 1 is supplied to a condenser, an expansion valve, and an evaporator, which also form an external refrigerant circuit (not shown), through a discharge passage 49 and a discharge flange (not shown), and is used for air conditioning in the vehicle compartment.

As shown in FIG. 10, in the 10-cylinder double-headed piston type compressor, the phase of the compression reaction force in each compression chamber is 1 for the sum of the front side and the sum of the rear side.
It will be shifted by 80 degrees. Here, when all the dead volumes of the compression chambers are uniform, the rotation n obtained by fast Fourier transform analysis of the sum of the compression reaction forces of the compression chambers.
The rotation tenth-order component as the next component has a regular waveform in which the same displacement is repeated 10 times, that is, an even number of times, in one rotation of the drive shaft 43. Therefore, the phase of the sum of the rotation tenth-order component on the front side and the phase of the sum on the rear side coincide with each other. Then, the rotational tenth-order component of the torque fluctuation derived from the compression reaction force of each compression chamber is completely superimposed and becomes the main component of the exciting force of the torsional vibration between the drive shaft 43 and the clutch (not shown).

In this case, the rotational fifth-order component as the rotational n / 2-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 43. 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 34 in order to reduce the rotational tenth-order component, as shown in FIG. The total amount on the front side and the total amount on the rear side are deviated from each other to reduce the phase. However, rotation 5
Similarly to the tenth-order component of rotation, a phase shift occurs between the front side and the rear side of the next 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 35, 3 are provided on the front side and the rear side.
The dead volume of 6 has been changed to 3 types. As the dead volumes of the compression chambers 35 and 36 are changed, the transition curves of the volumes and pressures of the compression chambers 35 and 36 differ from each other. That is, as shown in FIG. 7, there is a difference in the timing of pressure changes in the compression chambers 35 and 36 between the re-expansion stroke and the compression stroke between the small dead volume and the large dead volume. Also, a difference occurs in the pressure during overcompression in the compression stroke. In other words, the compression chambers 35 and 36 with the increased dead volume have the following transition curves.
The re-expansion stroke and the compression stroke are delayed, and the pressure at the time of over-compression is reduced.

Further, in the compressor of this embodiment, the suction valves 29a-1 to 29-5a corresponding to the compression chambers 35 and 36 having a large dead volume are formed to have a greater rigidity. Therefore, in the re-expansion / suction stroke, the intake valves 29a-1 to 29-5a having a large rigidity are opened with a delay, and as shown in FIG. 7, the delay in the pressure change in the compression chambers 35 and 36 is further increased. Become. Also, the discharge valve 31a
-1 to 31a-5 are also formed such that the ones corresponding to the compression chambers 35 and 36 having larger dead volumes have higher rigidity. Therefore, in the compression / discharge stroke, the discharge valves 31a-1 to 31a-5, which have higher rigidity, are opened later, and the delay in the pressure change in the compression chambers 35 and 36 becomes larger.

As a result, as shown in FIG. 8, between the compression chambers 35 and 36 having a small dead volume and the compression chambers 35 and 36 having a large dead volume, the transition curve of the compression torque per compression chamber is shown. , There is a difference in the torque peak position. Therefore, a phase shift occurs in the rotational 10th 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. Then, the total sum of the rotational 10th-order components on the front side and the rear side is reduced as compared with the case where the dead volume is not changed.

In the compressor of this embodiment, the difference between the maximum dead volume value and the minimum dead volume value is 0.8 cc, for example. This value corresponds to 4% of the reference suction volume of 20 cc in the cylinder bores 33-1 and 33-3 in which the dead volume expansion process is not performed. The expansion of the dead volume to this extent has almost no effect on the performance such as the compression efficiency.

By the way, generally, the manufacturing error of each component of 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.

Further, the dead volume of the front side compression chamber 35 and the rear side compression chamber 36 of one double-headed piston 34 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 the embodiment configured as described above, the following excellent effects are exhibited. (A) On the front side and the rear side, the dead volume of each compression chamber 35, 36 is changed to three types. As a result, the transition curves of the volume and pressure in the compression chambers 35, 36 are changed, and the compression chambers 35, 36 are changed.
The overlapped portion of the torque fluctuation due to the change of the compression torque is reduced. Then, in the 10-cylinder type double-headed piston type compressor, the rotational tenth-order component, which is the main component of the torque fluctuation that is the exciting force of the torsional vibration, is reduced. Therefore,
Due to the torsional vibration, 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 interior is reduced.

(B) Suction valves 29a-1 to 29a-5 corresponding to the compression chambers 35 and 36 of the cylinder bores 33-1 to 33-5, respectively.
The discharge valves 31a-1 to 31a-5 are formed so that the rigidity of the discharge valves 31a-1 to 31a-5 corresponding to the compression chambers 35 and 36 having a large dead volume is increased. Therefore, in the compression chambers 35 and 36 having different dead volumes, the suction valve 29
The valve opening timings of the a-1 to 29a-5 and the discharge valves 31a-1 to 31a-5 are deviated. As a result, the transition curves of the volumes and pressures in the compression chambers 35 and 36 are changed, and the rotational tenth order component is reduced as in the case of (a).

(C) The difference between the maximum dead volume value and the minimum dead volume value corresponds to 4% of the reference suction volume in the cylinder bores 33-1 and 33-3 which are not subjected to dead volume expansion treatment. Is formed in. Therefore, in the compressor of this embodiment, even if the assembly tolerance is taken into consideration, the change of the dead volume of each compression chamber 35, 36 is ensured.

(D) The front side compression chamber 35 and the rear side compression chamber 36 of one double-headed piston 34 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 items (a) to (c), it is possible to reduce the rotational tenth-order component of the torque fluctuation and suppress the generation of the rotational fifth-order component.

(Second Embodiment) The second embodiment of the present invention will be described below.
An embodiment will be described based on FIGS. 11 and 12. In the second embodiment, in addition to the dead volume changing structure and the valve rigidity changing structure in the first embodiment,
The following configuration is added. That is, the suction valves 29a-1 to 29a-5 and the discharge valves 31a-1 to 31a-5 corresponding to the compression chambers 35 and 36 of the cylinder bores 33-1 to 33-5, respectively.
Is formed so as to change the contact area with the valve plate 30 (a factor that determines the valve opening pressure) according to the size of the dead volume in the compression chambers 35 and 36. In this case, the cylinder bore 33-1 with a large dead volume
The contact areas of the suction valves 29a-1 to 29a-5 and the discharge valves 31a-1 to 31a-5 with respect to the valve plate 30 are set to be larger as they correspond to the compression chambers 35 and 36 of 33-5. .

That is, the suction valves 29a-1 and 29a-3 corresponding to the cylinder bores 33-1 and 33-3 having the minimum dead volume have a small contact area with the valve plate 30 by reducing the width of the opening / closing portion 29b. Is formed. The intake valve 29a-5 corresponding to the intermediate dead volume cylinder bore 33-5 has an opening / closing section 2
By making the width of 9b in the middle, the valve plate 30
It is formed so that the contact area with respect to is in the middle.
Cylinder bores 33-2 and 33-4 with maximum dead volume
The suction valves 29a-2 and 29a-4 corresponding to
The contact area with the valve plate 30 is increased by increasing the width of b.

Similarly, the discharge valves 31a-1 and 3 corresponding to the cylinder bores 33-1 and 33-3 having the minimum dead volume are provided.
1a-3, by reducing the width of the opening and closing portion 31b,
The contact area with the valve plate 30 is reduced. The discharge valve 31a-5 corresponding to the intermediate dead volume cylinder bore 33-5 has an opening / closing portion 31b.
Is formed so that the contact area with the valve plate 30 becomes intermediate. The discharge valves 31a-2 and 31a-4 corresponding to the cylinder bores 33-2 and 33-4 having the maximum dead volume are formed so that the contact area with the valve plate 30 is increased by increasing the width of the opening / closing part 31b. ing.

As described above, for the intake valves 29a-1 to 29a-5, the cylinder bore 33 having a large dead volume is used.
The ones corresponding to -1 to 33-5 have a higher rigidity and a larger contact area with the valve plate 30. In addition, the discharge valves 31a-1 to 31
Regarding a-5 as well, the one corresponding to the cylinder bores 33-1 to 33-5 having a larger dead volume has a higher rigidity and a larger contact area with the valve plate 30.

Here, the larger the contact area between the suction valves 29a-1 to 29a-5 and the discharge valves 31a-1 to 31a-5 and the valve plate 30, the larger the amount of lubricating oil interposed therebetween. Become. Then, the adhesion between the suction valves 29a-1 to 29a-5 and the discharge valves 31a-1 to 31a-5 and the valve plate 30 due to the surface tension of the lubricating oil becomes large.
Therefore, the suction valves 29a-1 to 29a-5 and the discharge valve 31a
There is a delay in the valve opening timing of -1 to 31a-5.

With this structure, as shown in FIG. 12, in the re-expansion / suction stroke of the compressor, the suction valves 29a-1 to 29-5a having a large rigidity and a large contact area are opened with a delay. The delay of the pressure change in the compression chambers 35 and 36 is further expanded. Also in the compression / discharge process, the discharge valves 31a-1 to 31a-5, which have a large rigidity and a large contact area, are opened later, and the delay in the pressure change in the compression chambers 35 and 36 is further expanded.

Therefore, in the compressor of the second embodiment, the effect of the first embodiment, that is, the effect of suppressing the generation of the rotational fifth-order component while reducing the rotational tenth-order component, It can be further improved.

The present invention can be modified and embodied as follows. (1) The dead volume of each compression chamber 35, 36 is changed by providing a recess in the head of the double-headed piston 34.

(2) The dead volume of each compression chamber 35, 36 is changed by providing a groove in the head of the double-headed piston 34. (3) The dead volumes of the compression chambers 35 and 36 are changed by changing the lengths of the cylinder bores 33-1 to 33-5.

The dead volumes of the compression chambers 35 and 36 can be changed with a simple structure even by the above-mentioned configurations (1) to (3). (4) In the second embodiment, the intake valves 29a-1 ...
To change only the contact area with the valve plate 30 without changing the rigidity of 29a-5 and the discharge valves 31a-1 to 31a-5.

(5) In either one of the intake valves 29a-1 to 29a-5 and the discharge valves 31a-1 to 31a-5,
At least one of the rigidity and the contact area with the valve plate 30 is configured to be changed according to the size of the dead volume of the corresponding compression chambers 35 and 36.

(6) The rigidity of the suction valves 29a-1 to 29a-5 and the discharge valves 31a-1 to 31a-5 should be changed only by changing either the plate thickness or the neck width. To configure.

(7) Only one of the suction valves 29a-1 to 29a-5 and the discharge valves 31a-1 to 31a-5 is
The contact area with the valve plate 30 is configured to be changed according to the size of the dead volume of the corresponding compression chambers 35 and 36.

Even with the above configurations (4) to (7), the valve opening timing is deviated due to the change in rigidity or the contact area, and the regularity of the compression torque in each compression chamber is lost.
The n-th rotation component of the torque fluctuation corresponding to the number of cylinders n is reduced.

(8) The present invention may be embodied in a double-headed piston type compressor having a number of cylinders other than those described in the above embodiment, for example, 6, 8 and 12 cylinders. (9) The dead volumes of the compression chambers 35 and 36 are formed so as to increase in order along the rotation direction of the drive shaft 43.

(10) The types of dead volumes of the compression chambers 35 and 36 on the front side and the rear side, respectively, are those other than those described in the above embodiment, for example, 4 types or 5 types.
Be kind.

(11) The difference between the minimum value and the maximum value of the dead volume should be changed within the range where the compression performance of the compressor does not extremely deteriorate, with the lower limit of 1% of the reference suction volume. (12) The expansion amount of the dead volume is set to a value other than those described in the above embodiments within a range in which the compression performance of the compressor is not extremely deteriorated.

(13) Set the reference suction volume to a value other than those described in the above embodiments. Above (8) ~
Even with the configuration (13), it is possible to reduce the n-th order rotation component corresponding to the number of cylinders n, and to suppress the occurrence thereof when the n-order rotation component is an odd-order component.

(14) Two or more types of dead volumes are changed in only one of the front compression chambers 35 and the rear compression chambers 36. (15) Embodying the present invention in a single-head piston compressor.

Even with the above configurations (14) and (15), it is possible to reduce the n-th order rotation component corresponding to the number of cylinders n. (16) Embodying the present invention in a wave cam plate type reciprocating compressor.

[0073]

As described above in detail, the present invention has the following excellent effects. At least two kinds of predetermined dead volumes are set in each compression chamber. Moreover, at least one of the intake valve and the discharge valve corresponding to each compression chamber is formed to have higher rigidity as it corresponds to the compression chamber having a larger dead volume. Further, at least one of the intake valve and the discharge valve corresponding to each compression chamber is formed such that the contact area with the valve plate becomes larger as the compression valve having a larger dead volume corresponds. Therefore, the change in the pressure in each compression chamber is changed, the rotational nth order component of the torque fluctuation corresponding to the number of cylinders n is greatly reduced, and the exciting force of the torsional vibration of the drive shaft-clutch system is suppressed. . Therefore, in the compressor and the auxiliary machine connected thereto, the resonance phenomenon excited by the torsional vibration is reduced, and the noise level in the vehicle interior can be lowered.

Further, there is a difference of 1% or more between the maximum dead volume value and the minimum dead volume value of each compression chamber 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, combined with the above effect, it is possible to suppress the generation of the rotational n / 2nd order component while reducing the rotational nth 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.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a compressor of a first embodiment.

FIG. 2 is an exploded perspective view showing a valve structure and its related structure.

FIG. 3A is an explanatory diagram showing a changed state of a dead volume of each compression chamber on a front side and a rear side in FIG.

FIG. 4 is a perspective view showing a suction valve forming plate of the valve assembly in an enlarged manner as seen from the opposite direction to FIG.

FIG. 5 is an enlarged perspective view showing a discharge valve forming plate of the valve assembly.

6 is a sectional view taken along line 6-6 of FIG.

FIG. 7 is an explanatory view showing the relationship between the shaft rotation angle and the bore pressure.

FIG. 8 is an explanatory diagram showing a relationship between a shaft rotation angle and a compression torque per compression chamber.

FIG. 9 is an explanatory diagram showing a reduction of a rotation tenth-order component and a change of a rotation fifth-order component.

FIG. 10A is an explanatory diagram regarding a superimposition phenomenon of a total sum on the front side and a total sum on the rear side regarding a fifth-order rotation component and FIG. 10B regarding a tenth-order rotation component.

FIG. 11 is a cross-sectional view showing the main parts of the compressor of the second embodiment.

FIG. 12 is an explanatory diagram showing the relationship between the shaft rotation angle and the bore pressure in the second embodiment.

[Explanation of symbols]

21, 22 ... Cylinder bores forming part of the housing, 23, 24 ... Valve structure, 25 ... Front housing forming part of the housing, 26 ... Rear housing forming part of the housing, 29a-1 to 29a -5 ... suction valve, 29b ... opening / closing part, 29c ... neck part, 30 ... valve plate, 31a-1 to 31a-5 ... discharge valve, 31b ... opening / closing part,
31c ... Neck, 33-1 to 33-5 ... Cylinder bore, 34 ...
Double-headed pistons, 35, 36 ... Compression chambers, 42 ... Crank chambers, 43 ... Drive shafts, 45 ... Swash plates as cam plates.

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

Claims (8)

[Claims] 1. A drive shaft is supported inside a housing to form a crank chamber, 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 housed in a reciprocating manner to form a compression chamber between the piston and a valve assembly facing the piston, and an intake valve and a discharge valve for opening and closing the compression chamber are formed on the valve assembly. A reciprocating compressor in which a cam plate is integrally rotatably attached to the drive shaft, and the piston is reciprocated in conjunction with the rotation of the cam plate to compress the refrigerant gas. Each compression chamber has a predetermined dead volume, and the larger the dead volume of the compression chamber corresponding to at least one of the intake valve and the discharge valve, the greater the rigidity. Reciprocating compressor, characterized in that formed to be larger. 2. The reciprocating compressor according to claim 1, wherein the suction valve and the discharge valve are changed in rigidity by changing a plate thickness thereof. 3. The reciprocating motion according to claim 1, wherein the intake valve and the discharge valve have an opening / closing portion and a neck portion, and the rigidity is changed by changing the width of the neck portion. Type compressor. 4. A drive shaft is supported inside the 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 housed in a reciprocating manner to form a compression chamber between the piston and a valve assembly facing the piston, and an intake valve and a discharge valve for opening and closing the compression chamber are formed on the valve assembly. A reciprocating type in which a valve plate is sandwiched, a cam plate is integrally rotatably mounted on the drive shaft, and the piston is reciprocated in conjunction with the rotation of the cam plate to compress the refrigerant gas. In the compressor, each of the compression chambers has a predetermined dead volume, and at least one of the suction valve and the discharge valve corresponds to the dead volume of the compression chamber. Reciprocating compressor, wherein the contact area of the valve plate is formed to be larger as having a large. 5. 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. Claims 1 to 4 characterized
A reciprocating compressor according to any one of the above. 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 size of the dead volume of each compression chamber on the front side and the size of the dead volume of each compression chamber on the rear side are the same in the rotational direction of the drive shaft. The reciprocating compressor according to claim 6. 8. The reciprocating compressor according to claim 6, wherein the dead volume on the front side and the dead volume on the rear side are formed to have the same size for one double-headed piston. .