JPH0458077A - Swash plate type compressor - Google Patents

Abstract

PURPOSE:To secure a clearance between each position and each cylinder bore by forming each bulkhead between respective cylinder bores with each groove in the end face of a cylinder block, and thereby restraining each cylinder bore adjacent to each cylinder bore which is in a discharge stroke, from being elastically deformed. CONSTITUTION:Each bulkhead 1b and 2b between adjacent cylinder bores 12 is formed with each groove 26 a part of which is opened to the side of each valve plate 3 and 4. By this constitution, when each cylinder bore 12 which is in a discharge stroke, is expanded, deformation due to the expansion is absorbed as each bulkhead 1b and 2b on the side of each cylinder bore 12 across each groove 26 is deformed, each bulkhead on the side of each adjacent cylinder bore 12 will never be deformed. This thereby restrains each cylinder bore 12 adjacent to each cylinder bore 12 which is in a discharge stroke, from being elastically deformed, and a clearance between each piston 13 and each cylinder bore 12 is secure, so that each piston 13 is thereby smoothly moved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a swash plate compressor equipped with a large number of pistons that reciprocate within a cylinder bore formed in a cylinder block, and specifically relates to a swash plate compressor that has a high discharge pressure. The present invention relates to a swash plate compressor with improved piston sliding properties when operating under certain conditions.

[Prior Art] In this type of swash plate compressor, as shown in FIG. 7, cylinder bores 41 are located on the same circumference around a drive shaft 43 rotatably supported by a cylinder block 42. , evenly spaced from each other. Each cylinder bore 41
are partitioned by solid partition walls 42a. The pistons that perform compression operations by reciprocating within each cylinder bore 41 do not perform the same operation at the same time, but rather reciprocate with phases shifted from each other, so that the pressure state within each cylinder bore 41 changes. different. For example, when the cylinder bore 41 of No. 3 in Fig. 7 is in the discharge stroke, the adjacent cylinder bore 41 of No. 2 is in the suction stroke,
4 cylinder bore 41 is in the compression stroke, both are N
The internal pressure of the bore is lower than that of the cylinder bore 41 of α3.

[Problem to be solved by the invention] In the conventional compressor, the compressor is not operated under conditions where the discharge pressure is particularly high (i.e., when the cooling load is large or when the heat exchange rate in the condenser is low). In this case, as shown in Fig. 8, cylinder bore 4] (in the figure, No.
, 3) expands, Nα2 and Nα in the suction stroke and compression stroke next to the cylinder bore 41 are expanded.
The partition wall 42a between the cylinder bores 41 of No. 4 and No. 4 is elastically deformed toward the inside of the cylinder bores 41 of No. 2 and No. 14. Therefore, there is a problem that there is no clearance between the piston and the cylinder bore 41 in the elastically deformed portion, and the friction between the piston and the cylinder bore 41 increases, making it easy for seizure to occur between the two. Additionally, in order to reduce the weight of compressors in recent years, the housing, cylinder block, piston, etc. are made of aluminum alloy, and the surface of the piston is coated with fluororesin to prevent seizure of the piston and cylinder bore due to adhesion of similar metals. Some have been. In this case, there is a problem that when the piston moves through the elastically deformed portion of the cylinder bore, the coating peels off, reducing sealing performance and making seizure more likely.

The present invention has been made in view of the above problems, and includes:
The purpose of this is to suppress the elastic deformation of the cylinder bore adjacent to the cylinder bore during the high-pressure discharge stroke, secure the clearance between the cylinder bore and the piston, maintain the sliding properties of the piston in good condition, and maintain the durability of the piston and cylinder bore. An object of the present invention is to provide a swash plate compressor that can improve seizure resistance.

[Means for Solving the Problems] In order to achieve the above object, in the invention as set forth in the first claim, a cylinder block having front and rear/S gussets joined to both front and rear ends is provided with a cylinder block that is connected to a cylinder block that is connected to a cylinder block that is connected to a cylinder block that is connected to a cylinder block that is connected to a cylinder block that is connected at both front and rear ends of the cylinder block. In order to accommodate a plurality of reciprocating pistons, a cylinder bore is formed so that its center is located around the drive shaft,
A groove was formed in the partition wall between each cylinder bore on the end face of the cylinder block.

Further, in the invention as set forth in claim 2, in order to house a plurality of pistons that reciprocate with rotation of the drive shaft in a cylinder block in which front and rear housings are joined at both front and rear ends via valve plates, forming a cylinder bore such that its center is located around the drive shaft;
A fitting hole was formed in the valve plate side end surface of the partition wall between each cylinder bore, and a pin partially fixed to the valve plate was inserted into the fitting hole.

[Operation] When the compressor is operated under conditions where the discharge pressure is high, and the pressure in the cylinder bore in the discharge stroke becomes higher than the pressure in both adjacent cylinder bores, the cylinder bore in the discharge stroke tends to expand.

In the first aspect of the invention, since there is a groove in the partition wall between adjacent cylinder bores, one end of which opens toward the valve plate, when the cylinder bore expands during the discharge stroke,
By deforming the partition wall on the cylinder bore side across the groove, deformation due to expansion is absorbed, and the partition wall on the adjacent cylinder bore side does not deform. Therefore, elastic deformation of the cylinder bore adjacent to the cylinder bore in the discharge stroke is suppressed, and a clearance between the cylinder bore and the piston is ensured, so that the piston can move smoothly.

On the other hand, in the second aspect of the invention, since the partition wall between adjacent cylinder bores and the valve plate are fixed by the pin, even if the cylinder bore in the discharge stroke attempts to expand, the partition wall between the adjacent cylinder bores will not be deformed. The pin prevents deformation of adjacent cylinder bores.

[Example 1] Hereinafter, a first example embodying the present invention will be described with reference to FIGS. 1 to 4.

As shown in FIG. 2, both ends of cylinder blocks 1 and 2, which are disposed opposite each other in the front and rear, are closed by front and rear housings 5°6 through valve plates 3 and 4, respectively.
They are connected and fixed by a plurality of bolts 7. A swash plate chamber 8 is formed in the mounting portion of the cylinder blocks 1 and 2,
Both cylinder blocks 1. A swash plate 11 is housed in shaft holes la and 2a extending through the center of the drive shaft 2, and is fitted onto a drive shaft 10 which is rotatably supported via a radial bearing 9. The cylinder block 1°2 has a plurality of pairs (5 pairs in this example) of cylinder bores 12.
The pistons 13 are formed parallel to the drive shaft IO and at the same circumferential position with the drive shaft 10 as the center, and a double-headed piston 13 is slidably accommodated in each cylinder bore 12 .

Each piston 13 is moored to the swash plate 11 via a shoe 14, and is reciprocated within the cylinder bore 12 by the rocking of the swash plate 11 as the drive shaft 10 rotates.
From the suction chamber 15.16 formed in the suction valve mechanism 17.1
8 to the compression chamber Pf.

The refrigerant gas is sucked into Pr and the compressed refrigerant gas is discharged to the discharge chamber 21.22 via the valve mechanism 19.20.
It is designed to discharge to. The swash plate chamber 8 is communicated with a suction chamber 15.16 through suction passages 23.24 formed in the cylinder blocks 1 and 2, and is introduced into the swash plate chamber 8 through a suction port 25 connected to an external cooling circuit (not shown). The refrigerant gas passes through the suction passages 23 and 24 and enters the suction chamber 15.
16.

As shown in FIG. 1, in the partition walls 1b and 2b between each cylinder bore 12, there is a groove 26 at a position equidistant from both adjacent cylinder bores 12, one end of which opens toward the valve plate 3°4 side.
is formed. In other words, the partition walls 1b, 2b between the cylinder bores 12 are doubled at the end portions of the valve plates 3, 4 with the groove 26 in between. The depth of the groove 26 is 5
mm or more is preferable. Note that the groove 26 is the suction passage 23.2.
4 or the bolt insertion hole 7a.

Next, the operation of the compressor configured as described above will be explained.

Since the front side and the rear side have the same effect, the front side will be explained (the same applies to the second embodiment).

Now, when the swash plate 11 is rotated by the rotation of the drive shaft 10, each piston 13 is reciprocated in the left-right direction in FIG. 2 within the cylinder bore 12, and refrigerant gas is sucked, compressed, and discharged. The pressure inside the cylinder bore 12 becomes highest when the piston 13 moves through the discharge stroke region, and at that time the cylinder bore 12 tends to expand. For example, No,
Assuming that the cylinder bore 12 of No. 3 is in the discharge stroke, as shown in FIG. 3, due to the expansion of the cylinder bore 12,
A force acts on the partition wall 1b between the adjacent cylinder bores 12 of Nα2 and Nα4 in the direction of deforming the partition wall 1b toward the inside of the cylinder bores 12 of Nα2 and Nα4. Since the partition wall 1b is in a free state on the valve plate 3 side, deformation occurs in a state where the amount of deformation is greatest on the end face side. However, since the partition wall 1b has the groove 26, as shown in FIG. 4, the portion of the partition wall 1b on the side of the cylinder bore 12 in the discharge stroke across the groove 26 deforms, thereby absorbing the deformation caused by expansion. , deformation of adjacent cylinder bores 12 is suppressed. Therefore, even if the cylinder bore 12 expands during the discharge stroke, the adjacent cylinder bore 12 hardly deforms, a clearance between the cylinder bore 12 and the piston 13 is ensured, and the piston 13 slides smoothly.

E Example 2] Next, a second embodiment will be described with reference to FIGS. 5 and 6.

In the embodiment, the partition wall lb between the cylinder bores 12.

2b, a portion where elastic deformation is likely to occur is actively formed, and this portion absorbs the expansion of the cylinder bore 12 and prevents the deformation from spreading to other portions. Deformation of the partition wall due to expansion of the cylinder bore 12 is directly prevented.

Fitting holes 27 are formed in the end faces of the valve plates 3 and 4 in the partition walls 1b and 2b between the respective cylinder bores 12. On the other hand, fitting holes 28 are also formed in the valve plates 3 and 4 at positions corresponding to the fitting holes 27. And pin 29
passes through the fitting hole 28 and is fitted into the fitting hole 27, and the partition wall 1
b, 2b are fixed to the valve plates 3, 4 by pins 29. Therefore, in this embodiment, when the cylinder bore 12 in the discharge stroke is about to expand, the partition walls 1b, 2b between the cylinder bores 12 are fixed to the valve plates 3, 4 by the pins 29, so that movement is prevented. Bulkhead lb.

Deformation of 2b is likely to occur if the end is a free end, but
This is unlikely to occur if the ends are constrained. Therefore, even if the cylinder bore 12 during the discharge stroke attempts to expand, the partition walls 1b, 2b are prevented from deforming, and the adjacent cylinder bore 12 is prevented from deforming.
2 is suppressed, a clearance between the cylinder bore 12 and the piston 13 is secured, and the piston 13 slides smoothly.

Further, in the configuration of this embodiment, the pins 29 for restraining the partition walls 1b and 2b can also be used as positioning pins when assembling the compressor.

Note that the present invention is not limited to the above-described embodiments, and for example, the suction chamber 15.16 is placed outside the discharge chamber 21.22.
It can be applied to compressors with a configuration in which the compressor is placed inside, it can be applied to variable capacity swash plate type compressors, and it can also be applied to wobble plate type (wobble type) compressors, which are limited to double-headed piston type compressors. You may.

[Effects of the Invention] As detailed above, according to the present invention, the elastic deformation of the cylinder bore adjacent to the cylinder bore during the discharge stroke is suppressed, the clearance between the cylinder bore and the piston is secured, and the piston always slides smoothly. This improves the seizure resistance of the piston and cylinder bore. Furthermore, when the piston and cylinder block are made of aluminum alloy to reduce weight and the peripheral surface of the piston is coated with fluororesin, peeling of the coating layer is prevented and sealing performance is ensured over a long period of time.

[Brief explanation of the drawing]

1 to 4 show a first embodiment embodying the present invention, in which FIG. 1 is a sectional view taken along line I-I in FIG. 2, FIG. 2 is a vertical sectional view of the compressor, and FIG. Fig. 3 is a schematic diagram showing the operation, Fig. 4 is a sectional view taken along the line N-IV in Fig. 3, Figs. 5 and 6 show the second embodiment, and Fig. 5 corresponds to Fig. 3. 6 is a partial sectional view taken along the line ■-■ in FIG. 5, FIG. 7 is a diagram corresponding to FIG. 1 of the conventional device, and FIG. 8 is a schematic diagram showing the deformed state of the cylinder bore. be. Cylinder blocks 1, 2, bulkheads 1b, 2b, valve plates 3, 4, drive shaft 10, cylinder bore 12, piston 13, groove 26, fitting hole 27, fitting hole 28, pin 29゜Patent applicant Toyota Jidosha Co., Ltd. Loom factory agent
Patent attorney Hironobu Onda (and 1 other person) Figure 4

Claims (2)

[Claims] 1. In order to accommodate a plurality of pistons that reciprocate as the drive shaft rotates, a cylinder bore is formed so that its center is located around the drive shaft, and the cylinder block has front and rear housings joined to both front and rear ends. A swash plate compressor with grooves formed in the partition wall between each cylinder bore on the end face of the block. 2. In order to house a plurality of pistons that reciprocate as the drive shaft rotates in a cylinder block with front and rear housings joined to both front and rear ends via valve plates, the cylinder bores are arranged so that their centers are located around the drive shaft. A swash plate compressor having a fitting hole formed in the valve plate side end face of the partition wall between each cylinder bore, and a pin partially fixed to the valve plate inserted into the fitting hole.