KR101128756B1 - Scroll type compressor - Google Patents

Abstract

SUMMARY A back pressure control valve provides a scroll compressor that can reliably reduce power loss or poor compression under a wide range of operating conditions while exhibiting excellent controllability and responsiveness.

In the scroll compressor of the present invention, a back pressure control valve 72 is formed between the discharge chamber 47 and the back pressure chamber 39. The back pressure control valve 72 has a first valve chamber 74a communicated by the discharge chamber 47 and the high pressure passage 75, and a second valve communicated by the back pressure chamber 39 and the back pressure passage 71b. The chamber 74b and the third valve chamber 74c communicated by the suction chamber 42 and the low pressure passage 71a are provided in this order. Moreover, the back pressure control valve 72 is the 1st hydraulic pressure surface S1 located in the 1st valve chamber 74a, the 2nd hydraulic pressure surface S2 located in the 2nd valve chamber 74b, and 3rd It has the valve body 76 which has the 3rd hydraulic pressure surface S3 located in the valve chamber 74c. The hydraulic pressure area of 3rd hydraulic pressure surface S3 is larger than the hydraulic pressure area of 1st hydraulic pressure surface S1, and is larger than the hydraulic pressure area of 2nd hydraulic pressure surface S2.

Scroll compressor

Description

Scroll Compressor {SCROLL TYPE COMPRESSOR}

The present invention relates to a scroll compressor.

A scroll compressor of the related art is disclosed in Fig. 5 of Patent Document 1. This compressor has a housing, a fixed scroll, and a movable scroll, and the suction chamber, the compression chamber, the discharge chamber, and the back pressure chamber are formed by these. In this compressor, the fixed scroll and the movable scroll are pressurized by the back pressure in the back pressure chamber.

In more detail, high pressure, such as a discharge chamber, is introduce | transduced into a back pressure chamber through a fixed throttle, and the adjustment valve is formed between a back pressure chamber and a suction chamber. In this adjustment valve, the back pressure passage and the low pressure passage are connected to the valve chamber. The back pressure passage communicates the back pressure chamber and the valve chamber, and the low pressure passage communicates the valve chamber and the suction chamber. In the valve chamber, a ball-shaped valve body is housed in an elastically supported state to close the back pressure passage.

In this compressor, in the control valve, the valve body is operated by the differential pressure of the back pressure in the back pressure chamber and the low pressure in the suction chamber, and the back pressure is adjusted. Then, the movable scroll is pressed against the fixed scroll by a load based on the back pressure. When the back pressure is appropriate by the adjustment valve, the reduction of power loss and the reduction of compression failure can be realized.

Patent document 1: Unexamined-Japanese-Patent No. 57-76291

DISCLOSURE OF INVENTION

Problems to be Solved by the Invention

However, in the conventional scroll compressor, the back pressure and the low pressure, which are not very high pressures, act only on the valve body in the regulating valve. For this reason, this scroll compressor has a problem of controllability of the back pressure.

Moreover, in the general scroll type compressor, as shown in FIG. 8, it is ideal for the reduction of a power loss and a compression failure to increase back pressure Pb (load) with the increase of discharge pressure Pd as a high pressure. In this point, in the scroll compressor, when the fixed throttle and the adjustment valve are set so that the compression failure is not generated in the state where the discharge pressure Pd is high, the back pressure Pb (load) is too high in the state where the discharge pressure Pd is low, which is indicated by hatching. Causes power loss in the part. That is, in the scroll compressor, it is difficult to secure a sufficient back pressure necessary under all the operating conditions, and there is a possibility of generating a power loss or a compression failure.

Moreover, since the said scroll type compressor introduces high pressure into a back pressure chamber through a fixed throttle, when the internal diameter of a fixed throttle is large, compression efficiency worsens, and when the internal diameter of a fixed throttle is small, the process becomes difficult in design. There is also.

For this reason, as disclosed in Unexamined-Japanese-Patent No. 11-132165, not only back pressure and low pressure but also high pressure can be considered. In this case, as compared with the case where a fixed throttle and an adjustment valve are employ | adopted, the back pressure control valve improves controllability of back pressure. In addition, it is easy to realize the back pressure Pb (load) according to the discharge pressure Pd, and power loss and poor compression can be reduced under a wide operating condition.

However, even if the back pressure, the low pressure, and the high pressure are applied to the valve body, as disclosed in Japanese Patent Laid-Open No. 11-132165, if the back pressure acts largely on the valve body, the control target is greatly controlled by the control object. As a result, the valve body is not stabilized. For example, when the valve body moves due to the high back pressure and the back pressure chamber communicates with the suction chamber, the back pressure is immediately lowered, this time the valve body moves in the opposite direction, and the valve body exhibits unstable behavior. In this case, the responsiveness of the back pressure control valve is concerned.

Moreover, if high pressure acts largely on a valve body, it will become difficult to follow a valve body with respect to the fall of low pressure. In this case, the power loss is large under low load conditions under high pressure and high load conditions.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional situation, and provides a scroll compressor that can reliably reduce power loss or poor compression under a wide range of operating conditions while the back pressure control valve exhibits excellent controllability and responsiveness. It is a problem to be solved.

The scroll compressor of the present invention has a housing, a fixed scroll, and a movable scroll, whereby a suction chamber, a compression chamber, a discharge chamber, and a back pressure chamber are formed, and the fixed scroll and the movable scroll are formed by the back pressure in the back pressure chamber. In the scroll compressor that is pressurized with each other,

A back pressure control valve is formed between the discharge chamber or the compression chamber and the back pressure chamber and / or between the back pressure chamber and the suction chamber,

The back pressure control valve includes a first valve chamber in communication with the discharge chamber or the compression chamber and the high pressure passage, a second valve chamber in communication with the back pressure chamber and the back pressure passage, and a third valve in communication with the suction chamber and the low pressure passage. Take the threads in this order,

Moreover, the back pressure control valve has a valve having a first hydraulic pressure surface positioned in the first valve chamber, a second hydraulic pressure surface positioned in the second valve chamber, and a third hydraulic pressure surface positioned in the third valve chamber. With a sieve,

The pressure receiving area of the third pressure receiving surface is larger than the pressure receiving area of the first pressure receiving surface, and is larger than the pressure receiving area of the second pressure receiving surface (claim 1).

In the scroll compressor of the present invention, the back pressure control valve acts on the valve body not only with the back pressure and the low pressure but also with a high pressure, so that the controllability of the back pressure is improved as compared with the case where the fixed throttle and the regulating valve are employed. In addition, it is easy to realize the back pressure (load) according to the discharge pressure, and power loss and poor compression can be reduced under wide operating conditions. In addition, when the first valve chamber communicates with the compression chamber, the compression chamber needs to be maintained at a high pressure that can realize controllability of the back pressure and the like.

Moreover, in this scroll type compressor, since the hydraulic pressure area of a 3rd hydraulic pressure surface is larger than the hydraulic pressure area of a 2nd hydraulic pressure surface, back pressure does not act largely on a valve body. For this reason, the valve body is stabilized because the control target is not largely controlled by the control target. For this reason, the back pressure control valve exhibits excellent response.

Moreover, in this scroll type compressor, since the hydraulic pressure area of a 3rd hydraulic pressure surface is larger than the hydraulic pressure area of a 1st hydraulic pressure surface, a high pressure does not act too much on a valve body. For this reason, a valve body is easy to follow also about the fall of low pressure, and a power loss can be reduced under the load conditions with low low pressure and high high pressure.

Therefore, with the scroll compressor of the present invention, the back pressure control valve can exhibit excellent controllability and responsiveness. In addition, the scroll compressor can more reliably reduce power loss and poor compression under wide operating conditions.

In addition, the scroll compressor of the present invention does not necessarily require a sensor for detecting high pressure or low pressure, a controller for calculating a load condition, and a displacement of the valve element, so that the manufacturing cost can be reduced.

The back pressure control valve may be formed between the back pressure chamber and the suction chamber. And this back pressure control valve can have a valve seat between a 2nd valve chamber and a 3rd valve chamber (claim 2). In this case, the discharge chamber or the compression chamber and the back pressure chamber may be communicated by the air supply passage. Simple fixed throttles may be formed in the air supply passage. In this case, since only the high pressure introduced into the back pressure chamber is limited to the back pressure control valve to the minimum while being discharged to the suction chamber, the high pressure is not unnecessarily discharged to the suction chamber, thereby exhibiting excellent compression efficiency.

The back pressure control valve may be formed between the discharge chamber and the back pressure chamber. And this back pressure control valve can have a valve seat between a 1st valve chamber and a 2nd valve chamber (claim 3). In this case, the back pressure chamber and the suction chamber can be communicated by the bleeding passage. A simple stationary throttle can also be formed in the bleed passage.

It is preferable that the valve body has a tapered portion facing the valve seat, and the tapered portion is reduced in diameter toward the second valve chamber side (claim 4). In this case, the opening degree change with respect to the stroke change of a valve body can be made gentle, and spring design and selection become easy.

At least one of the first hydraulic pressure surface, the second hydraulic pressure surface, and the third hydraulic pressure surface may be formed of a bellows, a diaphragm, or the like.

The scroll compressor of the present invention can more reliably reduce power loss and poor compression under a wide range of operating conditions while the back pressure control valve exhibits excellent controllability and responsiveness.

Carrying out the invention  Best form for

EMBODIMENT OF THE INVENTION Hereinafter, Example 1, 2 which embodies this invention in the electric scroll type compressor is demonstrated, referring drawings.

(Example 1)

As shown in FIG. 1, the compressor of Example 1 is provided with the housing 10 which consists of a bottomed cylindrical front housing 11 and a lid-shaped rear housing 12. As shown in FIG. In the front housing 11, a bearing member 15 is formed, and a fixed scroll 16 is formed behind the bearing member 15. The front housing 11 and the rear housing 12 are accommodated in a state where the jersey member 15 and the fixed scroll 16 abut each other, so that the rear end of the front housing 11 and the front end of the rear housing 12 are They are opposed to each other and are fixed to each other by the bolts 13. The suction chamber 42 is formed by the front housing 11 and the accumulator member 15, and the discharge chamber 47 is formed by the fixed scroll 16 and the rear housing 12.

The accumulator member 15 consists of the cylindrical main-body part 17 and the flange part 18 which extends outward from the opening edge of the rear end of the main-body part 17. As shown in FIG. A shaft hole 19 penetrates through the center of the bottom wall 17a of the main body 17. The flange part 18 abuts against the step | step 21 formed in the inner peripheral surface of the front housing 11, and the front is fixed. On the rear end of the paper-making member 15, a rotation preventing pin 23a for regulating the rotation of the movable scroll 22 described later is fixed.

The bearing device 25 is formed in the center of the inner surface of the bottom wall 11a of the front housing 11, and the bearing device 26 is formed in the main-body part 17 of the storage member 15. As shown in FIG. The bearing devices 25 and 26 are supported so that each end part of the rotating shaft 24 extended in the axial direction back and forth can rotate. The sealing member 30 for sealing is interposed between the accumulator member 15 and the rotating shaft 24 by the circlip 31.

At the rear end of the rotation shaft 24, a circumferential eccentric pin 32 protrudes and is formed at a position eccentric from the center axis line of the rotation shaft 24. A cylindrical bush 33 is fitted and supported by the eccentric pin 32. In the substantially accompaniment part of the outer peripheral surface of the bush 33, the balance weight 35 extended in fan shape is formed integrally in the outer side. This balance weight 35 plays a role of canceling the centrifugal force accompanying the revolution of the movable scroll 22.

In addition, the fixed scroll 16 is formed by the base wall 16a and the outer circumferential wall 16b to form a bottomed tubular fixed side substrate 16c and the inner wall of the base wall 16a. It consists of the fixed side vortex wall 16d standing on the front surface.

On the other hand, the movable scroll 22 is formed between the bush 33 and the fixed scroll 16 via the bearing device 34. The movable scroll 22 consists of a disk-shaped movable side board | substrate 22a and the movable side swirl wall 22b which was erected on the back surface of the movable side board | substrate 22a.

 The fixed scroll 16 and the movable scroll 22 are engaged with each other via the vortex walls 16d and 22b so that the tip ends of the vortex walls 16d and 22b slide on the opposing substrates 16c and 22a. It is configured to do so. In the front surface of the movable side board | substrate 22a, the rotation stopper hole 37 which accommodates in the state which pinched the tip part of the rotation stopper pin 23a loosely is formed. A cylindrical ring 23b is loosely fitted in the rotation blocking hole 37, and the anti-rotation pin 23a slides and rotates the inner circumferential surface of the ring 23b.

A compression chamber 38 is formed between the fixed side substrate 16c and the fixed side vortex wall 16d, and the movable side substrate 22a and the movable side vortex wall 22b. Moreover, as a front side (back side opposite to the compression chamber 38 with the movable side board | substrate 22a between them) between the movable side board | substrate 22a, and between the movable side board | substrate 22a and the storage member 15, The back pressure chamber 39 to which the rear end of the rotating shaft 24 faces is formed in this. In addition, a suction region 41 is formed between the sheet member 15, the outer circumferential wall 16b, and the outermost circumferential portion of the movable side vortex wall 22b.

The suction chamber 42 and the suction region 41 in the front housing 11 are communicated with each other by the suction passage 43 formed in the lower portion of the front housing 11. In the suction chamber 42, the stator 44 is fixed to the inner circumferential surface of the front housing 11, and the rotor 45 is fixed to the rotation shaft 24 inside the stator 44. . The motor mechanism 40 is constituted by the rotor 45, the stator 44, and the rotation shaft 24, and the rotation shaft 24 and the rotor 45 are integrally rotated by energizing the stator 44. It is.

In addition, a suction port 46 connected to a front end of the main wall of the front housing 11 by a pipe to an evaporator (not shown) is formed therethrough. The evaporator is connected to the expansion valve and the condenser by piping. Compressors, evaporators, expansion valves and condensers comprise the refrigeration circuit of vehicle air conditioning equipment. The low pressure and low temperature refrigerant gas in the refrigerating circuit is supplied from the suction port 46 to the suction region 41 via the suction chamber 42 and the suction passage 43.

The discharge chamber 47 is formed between the rear end of the fixed side substrate 16c and the front end of the rear housing 12. A discharge port 48 penetrates through the center of the fixed side substrate 16c, and the compression chamber 38 and the discharge chamber 47 communicate with each other via the discharge port 48. In the rear end of the fixed side substrate 16c, a discharge valve (not shown) for opening and closing the discharge port 48 and a retainer 49 for restricting the opening degree of the discharge valve are formed in the discharge chamber 47. It is.

In the rear housing 12, the oil separation chamber 51 which extends in the up-down direction in the state mounted in the vehicle is formed behind the discharge chamber 47. As shown in FIG. A partition wall 52 is formed between the oil separation chamber 51 and the discharge chamber 47, and a discharge hole 53 communicating with the oil separation chamber 51 and the discharge chamber 47 penetrates the partition wall 52. Formed. In the oil separation chamber 51, an oil separator 55 for separating lubricating oil contained in the refrigerant gas is formed. The oil separator 55 has a cylindrical shape and is accommodated in the fitted state in the oil separation chamber 51. The refrigerant gas introduced from the discharge chamber 47 through the discharge hole 53 into the oil separation chamber 51 separates the lubricating oil by centrifugal separation by the oil separator 55, and the separated lubricating oil falls to the oil. It is stored in the separation chamber 51. The upper end of the oil separation chamber 51 located above the oil separator 55 is the discharge port 56, and the discharge port 56 is connected to the condenser of the refrigeration circuit by piping.

The lower end of the oil separation chamber 51 and the lower end of the discharge chamber 47 communicate with each other by the oil supply port 54, and the lower end of the discharge chamber 47 communicate with the back pressure chamber 39 by the air supply passage 57. It is. The air supply passage 57 is connected to the communication hole 59 penetrating through the outer circumferential wall 16b of the fixed scroll 16 and to a plate 61 interposed between the accumulator member 15 and the movable scroll 22. It is formed and consists of a slit 60 extending in an arc shape to the back pressure chamber 39. The slit 60 is a simple fixed throttle for narrowing the air supply passage 57 on the upstream side of the back pressure chamber 39. These are communicated in the order of the communication hole 59 and the slit 60 from an upstream side, and as shown in FIG. 2, the high pressure refrigerant gas in the discharge chamber 47 is supplied to the back pressure chamber 39 with lubricating oil. .

As shown in FIG. 1 and FIG. 2, the back pressure chamber 39 and the suction chamber 42 communicate with each other via the bleeding passage 71. The back pressure control valve 72 is formed in the bleeding passage 71. The bleeding passage 71 is a low pressure passage 71a for connecting the suction chamber 42 and the back pressure control valve 72, and a back pressure passage 71b for connecting the back pressure control valve 72 and the back pressure chamber 39. Is done.

The back pressure control valve 72 has the valve chamber 74 formed by the front housing 11 and the case 73, as shown in FIG. The valve chamber 74 has a first valve chamber 74a communicated by the discharge chamber 47 and the high pressure passage 75, and a second valve chamber communicated by the back pressure chamber 39 and the back pressure passage 71b. 74b and the 3rd valve chamber 74c which communicates with the suction chamber 42 and the low pressure passage 71a. The first to third valve chambers 74a to 74c are formed in this order from below to upward. Further, the valve chamber 74 may be formed by members other than the front housing 11 and the case 73. O rings 78a and 78b are formed between the front housing 11 and the case 73.

In the valve chamber 74, the valve body 76 is accommodated so that it can reciprocate up and down. The valve body 76 is integrally formed with the tapered portion 76a having a large diameter upward and the tapered portion 76a, and extends circumferentially coaxially with the tapered portion 76a from the lower end of the tapered portion 76a. Consisting of a body portion 76b. The taper portion 76a is reduced in diameter toward the second valve chamber 74b side. Moreover, the spring sheet 76c which holds the spring 77 mentioned later is formed in the upper surface of the taper part 76a.

The lower surface of the body portion 76b constitutes the first hydraulic pressure surface S1, and the cross-sectional area of the tapered portion 76a in the axially perpendicular direction constitutes the third hydraulic pressure surface S3. In addition, the difference between the cross-sectional area of the tapered portion 76a in the axial right angle direction and the cross-sectional area of the trunk portion 76b in the axial right angle, that is, the difference between the first hydraulic pressure surface S1 and the third hydraulic pressure surface S3 is the second hydraulic pressure surface ( S2) is comprised. As shown in FIG. 4, the hydraulic pressure area of 3rd hydraulic pressure surface S3 is larger than the hydraulic pressure area of 1st hydraulic pressure surface S1, and is larger than the hydraulic pressure area of 2nd hydraulic pressure surface S2. Moreover, the hydraulic pressure area of 3rd hydraulic pressure surface S3 is a sum of the hydraulic pressure area of 1st hydraulic pressure surface S1, and the hydraulic pressure area of 2nd hydraulic pressure surface S2.

As shown in FIG. 3, the taper part 76a is formed over the 3rd valve chamber 74c and the 2nd valve chamber 74b, and the fuselage | body part 76b is airtight in the 1st valve chamber 74a. It is formed so that it can slide. A valve seat 74d is formed between the third valve chamber 74c and the second valve chamber 74b.

The third valve chamber 74c is connected to the suction chamber 42 by the low pressure passage 71a, and the lower part of the second valve chamber 74b is connected to the back pressure chamber 39 by the back pressure passage 71b. There is. The valve seat 74d faces the tapered portion 76a of the valve body 76. The valve seat 74d is formed slightly larger in diameter than the maximum diameter of the taper part 76a, and the taper part 76a is able to slide in the airtight state in the 2nd valve chamber 74b. The O-ring 78a is formed between the low pressure passage 71a and the back pressure passage 71b.

The lower end of the first valve chamber 74a is connected to the discharge chamber 47 by the high pressure passage 75. An O ring 78b is formed between the high pressure passage 75 and the back pressure passage 71b. Moreover, between the ceiling in the valve chamber 74 and the spring seat 76c, the spring 77 which has elastic support in the direction in which the taper part 76a is seated on the valve seat 74d is formed.

The compressor configured as described above operates as follows. That is, when the rotation shaft 24 of the motor mechanism 40 shown in FIG. 1 is rotated by the operation of a vehicle driver, the eccentric pin 32 is rotated around the axial center of the fixed scroll 16. At this time, the movable scroll 22 is prevented from rotating due to the rotation stopping pin 23a sliding and rolling along the inner circumferential surface of the ring 23b, and only revolution is allowed. And the compression chamber 38 is moved by the revolving of the movable scroll 22, reducing a volume from the outer peripheral side of the vortex walls 16d, 22b of both scrolls 16, 22 to the center. For this reason, the refrigerant gas or the like enters into the suction region 41 from the suction port 46 via the suction chamber 42 and the suction passage 43 rather than the evaporator, and is sucked from the suction region 41 into the compression chamber 38 again. Is compressed. The refrigerant gas or the like compressed up to the discharge pressure is discharged from the discharge port 48 into the discharge chamber 47, introduced into the oil separation chamber 51 via the discharge hole 53, and the lubricating oil is separated there. The refrigerant gas from which the lubricating oil is separated is discharged from the oil separator 55 via the discharge port 56 to the condenser. In this way, air conditioning of the vehicle air conditioner is performed.

On the other hand, the lubricating oil separated from the refrigerant gas falls from the oil separator 55 and is stored in the oil separation chamber 51. As shown in FIG. 2, the lubricating oil stored in the oil separation chamber 51 is supplied to the back pressure chamber 39 via the slit 60 of the air supply passage 57 together with some refrigerant gas.

3, in the back pressure control valve 72, the high pressure passage 75 applies the discharge pressure Pd, which is the high pressure in the discharge chamber 47, to the first hydraulic pressure surface S1 of the valve body 76. Thus, the valve body 76 is to be moved upward. When the valve body 76 moves in the upward direction, the taper portion 76a moves away from the valve seat 74d, and the refrigerant gas in the back pressure chamber 39 passes through the back pressure passage 71b and the second valve chamber 74b. Through the valve seat 74d, the third valve chamber 74c, and the low pressure passage 71a, it is easily discharged to the suction chamber 42, and the back pressure Pb is lowered.

Moreover, in this back pressure control valve 72, the low pressure passage 71a applies the suction pressure Ps which is the low pressure in the suction chamber 42 to the 3rd hydraulic pressure surface S3 of the valve body 76, and the valve body 76 ) To move downward. When the valve body 76 moves downward, the taper part 76a becomes close to the valve seat 74d, and it becomes difficult for refrigerant gas, etc. of the back pressure Pb of the back pressure chamber 39 to be discharged | emitted to the suction chamber 42, and back pressure Pb rises.

In this way, this back pressure control valve 72 acts on not only the back pressure Pb and the suction pressure Ps but also the discharge pressure Pd to the valve body 76, compared with the case where a fixed throttle and an adjustment valve are employ | adopted. Controllability is improved. In addition, it is easy to realize the back pressure Pb (load) according to the discharge pressure Pd, and power loss and poor compression can be reduced under a wide operating condition.

Moreover, in this compressor, since the hydraulic pressure area of 3rd hydraulic pressure surface S3 is larger than the hydraulic pressure area of 2nd hydraulic pressure surface S2, back pressure Pb does not act largely on valve body 76. FIG. For this reason, since the control object is not largely controlled by the control object, the valve body 76 is stabilized. For this reason, the back pressure control valve 76 exhibits the excellent response.

Moreover, in this compressor, since the hydraulic pressure area of 3rd hydraulic pressure surface S3 is larger than the hydraulic pressure area of 1st hydraulic pressure surface S1, discharge pressure Pd does not act largely on valve body 76 either. For this reason, the valve body 76 tends to follow the fall of the suction pressure Ps.

For this reason, in the compressor of Example 1, as shown in FIG. 9, not only under the load conditions where the suction pressure Ps is high and the discharge pressure Pd is high, but also under the load conditions where the suction pressure Ps is low and the discharge pressure Pd is high, The loss can be made small. In addition, the compressor of the comparative example acts on the valve body of the back pressure regulating valve, and acts on the back pressure Pb, the suction pressure Ps, and the discharge pressure Pd, and the hydraulic pressure surface of the hydraulic pressure surface on which the suction pressure Ps acts and the discharge pressure Pd act. The hydraulic pressure area of is equalized. It can be seen that the compressor of Example 1 can exhibit excellent power performance under load conditions with a low suction pressure Ps as compared with the compressor of the comparative example. The scroll compressor having the suction pressure Ps around the movable scroll 22 is susceptible to the suction pressure Ps, and it is very practical to exhibit excellent power performance by the change of the suction pressure Ps.

Therefore, with this compressor, the back pressure control valve 72 can exhibit excellent controllability and responsiveness. In addition, the scroll compressor can more reliably reduce power loss and poor compression under wide operating conditions.

In particular, the compressor communicates the discharge chamber 47 and the back pressure chamber 39 by the air supply passage 57, and restricts the discharge pressure Pd introduced into the back pressure chamber 39 to the minimum in the back pressure control valve 72. It only sends it out to the suction chamber 42. For this reason, it is possible to exert excellent compression efficiency without discharging the discharge pressure Pd unnecessarily to the suction chamber 42.

Moreover, in this compressor, since the diameter of the taper part 76a of the valve body 76 is reduced toward the 2nd valve chamber 74b side, the opening degree change with respect to the stroke change of the valve body 76 is made smoothly. The spring 77 can be easily designed and selected.

In this compressor, since the sensors for detecting the discharge pressure Pd and the suction pressure Ps, the controller for calculating the load condition and displacing the valve body 76, etc. are not necessarily required, the manufacturing cost can be reduced. .

(Example 2)

In the electric scroll compressor of the second embodiment, as shown in FIG. 5, the discharge chamber 47 and the back pressure chamber 39 are connected by the air supply passage 57, and the back pressure control valve 82 is connected to the air supply passage 57. ) Is formed. The air supply passage 57 includes the high pressure passages 81a and 81b for connecting the discharge chamber 47 and the back pressure control valve 72, and the back pressure passage 81c for connecting the back pressure control valve 82 and the back pressure chamber 39. ) The back pressure chamber 39 and the suction chamber 42 are connected by the bleeding passage 71. The throttle 80 is formed in the bleeding passage 71.

As shown in FIG. 6, the back pressure control valve 82 has a valve chamber 84 formed by the front housing 11 and the case 83. The valve chamber 84 communicates with the discharge chamber 47 by the first valve chambers 84a and 84b communicated by the high pressure passages 81a and 81b, and the back pressure chamber 39 and the back pressure passage 81c. It consists of the 2nd valve chamber 84c, and the 3rd valve chamber 84d connected by the suction chamber 42 and the low pressure passage 85. As shown in FIG. The first to third valve chambers 84a and 84b to 84d are formed in this order from below to upward. The valve chamber 84 may also be formed by members other than the front housing 11 and the case 83. O-rings 88a and 88b are formed between the front housing 11 and the case 83.

In the valve chamber 84, the valve body 86 is accommodated so that it can reciprocate up and down. The valve body 86 is integral with the columnar head portion 86a and the head portion 86a, and extends coaxially with the head portion 86a coaxially from the lower end of the head portion 86a. The 86b is integrated with the head portion 86b, and the tapered portion 86c extends from the lower end of the head portion 86b, and the tapered portion 86c is integrated with the tapered portion 86c from the lower end of the tapered portion 86c. It consists of the trunk | drum part 86d extending coaxially and circumferentially. The taper portion 86c is reduced in diameter toward the second valve chamber 84c side.

The lower surface of the body portion 86d constitutes the first hydraulic pressure surface S1, and the upper surface of the head portion 86a constitutes the third hydraulic pressure surface S3. Moreover, the difference of the cross-sectional area of the lower surface of the head part 86a and the perpendicular | vertical angle of the trunk part 86d, ie, the difference of the 1st hydraulic pressure surface S1 and the 3rd hydraulic pressure surface S3, comprises the 2nd hydraulic pressure surface S2, have. As shown in FIG. 7, the hydraulic pressure area of 3rd hydraulic pressure surface S3 is larger than the hydraulic pressure area of 1st hydraulic pressure surface S1, and is larger than the hydraulic pressure area of 2nd hydraulic pressure surface S2. Moreover, the hydraulic pressure area of 3rd hydraulic pressure surface S3 is a sum of the hydraulic pressure area of 1st hydraulic pressure surface S1, and the hydraulic pressure area of 2nd hydraulic pressure surface S2.

As shown in FIG. 6, the body part 86d is formed so that it may slide in the airtight state in the 1st valve chamber 84a, and the taper part 86c is the 1st valve chamber 84b and the 2nd valve. It is formed over the yarn 84c. The valve seat 84e is formed between the 1st valve chamber 84b and the 2nd valve chamber 84c.

The third valve chamber 84d is connected to the suction chamber 42 by the low pressure passage 85, and the upper portion of the second valve chamber 84c is connected to the back pressure chamber 39 by the back pressure passage 81c. have. The valve seat 84e faces the tapered portion 86c of the valve body 86. The valve seat 84e is formed slightly larger in diameter than the maximum diameter of the taper part 86c, and the taper part 86c is able to slide in the airtight state in the 2nd valve chamber 84c. An O-ring 88a is formed between the low pressure passage 85 and the back pressure passage 81c.

The first valve chambers 84a and 84b are connected to the discharge chamber 47 by the high pressure passages 81a and 81b. An O ring 88b is formed between the high pressure passages 81a and 81b and the back pressure passage 81c. Moreover, between the ceiling in the valve chamber 84 and the upper surface of the head part 86a, the spring 87 which has elastic support force in the direction from which the taper part 86c moves away from the valve seat 84e is formed. The other configuration is the same as that of the compressor of the first embodiment.

In the back pressure control valve 82 of this compressor, the high pressure passage 81a applies the discharge pressure Pd in the discharge chamber 47 to the first hydraulic pressure surface S1 of the valve body 86, thereby applying the valve body 86. We want to move in the upward direction. When the valve body 86 moves upward, the taper part 86c approaches the valve seat 84e, and refrigerant gas etc. of the discharge pressure Pd in the discharge chamber 47 are made into the high pressure passage 81b, the 1st valve chamber. It is difficult to be supplied to the back pressure chamber 39 via the 84b, the valve seat 84e, the second valve chamber 84c, and the back pressure passage 81c, and the refrigerant gas in the back pressure chamber 39, etc., is scavenged passage 71. Back pressure Pb falls in the point which is easy to be discharged to the suction chamber 42 via (circle).

In the back pressure control valve 82, the low pressure passage 85 applies the suction pressure Ps in the suction chamber 42 to the third hydraulic pressure surface S3 of the valve body 86, thereby applying the valve body 86. We want to move in the downward direction. When the valve body 86 moves downward, the taper part 86c moves away from the valve seat 84e, and the refrigerant gas etc. of the discharge pressure Pd in the discharge chamber 47 are easy to be supplied to the back pressure chamber 39. FIG. The back pressure Pb rises.

Therefore, also in this compressor, the effect similar to the compressor of Example 1 can be exhibited.

As mentioned above, although this invention was demonstrated based on Example 1, 2, this invention is not limited to the said Example 1, 2, It can be said that it can change suitably and apply it in the range which does not deviate from the meaning. There is no need.

For example, although the said Example 1, 2 is an electric scroll type | mold compressor which incorporates the motor mechanism 40, the present invention can also be embodied in the scroll type | mold compressor which does not contain the motor mechanism 40. FIG.

In addition, the air supply passage 57 and the high pressure passage 75 may communicate the compression chamber 38 and the back pressure chamber 39 instead of the discharge chamber 47 and the back pressure chamber 39.

In addition, although the said Example 1, 2 pressed the movable scroll 22 to the fixed scroll 16 by back pressure, you may press the fixed scroll 16 to the movable scroll 22 by back pressure.

In the first and second embodiments, the first valve chambers 74a, 84a and 84b communicate with the discharge chamber 47, but the first valve chambers 74a, 84a and 84b communicate with the compression chamber 38. You can also In this case, since the compression chamber 38 needs to be maintained at a high pressure capable of realizing controllability of the back pressure, etc., the first valve chambers 74a, 84a, 84b are centered on the fixed scroll 16 and the movable scroll 22. It can be made to communicate with the compression chamber 38 of the side.

The present invention can be used for a vehicle air conditioner.

1 is a cross-sectional view of the electric scroll compressor of the first embodiment.

2 is a schematic configuration diagram of an electric scroll compressor of the first embodiment.

3 is a cross-sectional view of the back pressure control valve in the electric scroll compressor of the first embodiment.

4 is an explanatory diagram showing a pressure receiving surface of a valve body in the electric scroll compressor of the first embodiment.

5 is a schematic configuration diagram of an electric scroll compressor of a second embodiment.

6 is a cross-sectional view of the back pressure control valve in the electric scroll compressor of the second embodiment.

It is explanatory drawing which shows the hydraulic pressure surface of the valve body in the electric scroll compressor of Example 2. FIG.

Fig. 8 is a graph showing the characteristics and calculation outliers of the conventional scroll compressor.

9 is a graph showing the characteristics of the electric scroll compressor of the first and second embodiments.

* Description of the symbols for the main parts of the drawings *

10... Housing (11… front housing, 12… rear housing)

16... Fixed scroll

22 ... Movable scroll

42... Suction chamber

38... Compression chamber

47... Discharge chamber

39... Back pressure chamber

72, 82... Back pressure control valve

75, 81a, 81b... High pressure passage

74a, 84a, 84b... 1st valve chamber

71b, 81c... Back pressure passage

74b, 84c... 2nd valve chamber

71a, 85... Low pressure passage

74c, 84d... 3rd valve chamber

S1... 1st hydraulic pressure surface

S2... 2nd hydraulic pressure surface

S3... 3rd hydraulic pressure surface

76, 86... Valve body

74d, 84e... Valve seat

76a, 86c... Taper part

Claims (4)

A scroll compressor having a housing, a fixed scroll, and a movable scroll, in which a suction chamber, a compression chamber, a discharge chamber, and a back pressure chamber are formed, and the fixed scroll and the movable scroll are pressed against each other by back pressure in the back pressure chamber. In The back pressure control valve which controls the back pressure of the said back pressure chamber, The said back pressure control valve, Between the discharge chamber and the back pressure chamber, or between the compression chamber and the back pressure chamber, Alternatively, between the back pressure chamber and the suction chamber, Or between the discharge chamber and the back pressure chamber and between the suction chamber and the back pressure chamber, Or between the compression chamber and the back pressure chamber and between the back pressure chamber and the suction chamber, The back pressure control valve includes a first valve chamber in communication with the discharge chamber or the compression chamber and the high pressure passage, a second valve chamber in communication with the back pressure chamber and the back pressure passage, and a third valve in communication with the suction chamber and the low pressure passage. Take the threads in this order, Moreover, the back pressure control valve has a valve having a first hydraulic pressure surface positioned in the first valve chamber, a second hydraulic pressure surface positioned in the second valve chamber, and a third hydraulic pressure surface positioned in the third valve chamber. With a sieve, The hydraulic pressure area of the 3rd hydraulic pressure surface is larger than the hydraulic pressure area of the 1st hydraulic pressure surface, and is larger than the hydraulic pressure area of the 2nd hydraulic pressure surface. The method of claim 1, The back pressure control valve is formed between the back pressure chamber and the suction chamber, And the back pressure control valve has a valve seat between the second valve chamber and the third valve chamber. The method of claim 1, The back pressure control valve is formed between the discharge chamber and the back pressure chamber, The back pressure control valve has a scroll type compressor having a valve seat between the first valve chamber and the second valve chamber. The method according to claim 2 or 3, The valve body has a taper portion facing the valve seat, the taper portion of which is reduced in diameter toward the second valve chamber side.

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