KR20090060180A - Variable capacity compressor - Google Patents

Abstract

A variable capacity compressor is provided to prevent discharged fluid from being suddenly removed in a low discharging capacity area and maintain the tilt angle of an inclined plate to be stabilized. A variable capacity compressor(1) comprises a housing(2), a plurality of cylinder bores(8), a crank-case(10), a driving shaft(4), a rotor(11), a journal(13), a connection link(14), an inclined plate(15) and a plurality of pistons(9). The rotor is fixed to the driving shaft. The connection link connects the rotor and the journal to each other. The tilt angle of the inclined plate is varied with the rotation of the journal. The connection link rotates around the rotor and varies the tilt angle of the inclined plate with rotation and varies reciprocal stroke of each piston. In a first rotation supporting point(14a), the connection link is connected to the rotor and in a second rotation supporting point(14b), the connection link is connected to the journal. The location of the second rotation supporting point and the first rotation supporting point is set up in order to reduce head gap in a low discharging capacity area.

Description

Variable Capacity Compressor {VARIABLE CAPACITY COMPRESSOR}

The present invention relates to a variable displacement compressor for varying the discharge capacity of the piston by the inclination angle of the inclined plate.

As a conventional variable displacement compressor of this kind, there is one disclosed in Patent Document 1.

This variable displacement compressor 100 has a housing 101 as shown in FIG. The housing 101 has a cylinder block 101a, a front head 101b disposed on one end side of the cylinder block 101a, and a rear portion disposed through the valve plate 102 on the other end side of the cylinder block 101a. The head 101c is mainly assembled by assembling.

The drive shaft 103 is disposed in the center of the housing 101. Both end sides of the drive shaft 103 are rotatably supported by the housing 101 via the radial bearing portion 104 and the radial bearing portion 105.

In the cylinder block 101a, a plurality of cylinder bores 106 are formed on a circumference around the drive shaft 103, and the pistons 107 are disposed in the cylinder bores 106 so as to be slidable, respectively. It is. In the front head 101b, the crank chamber 108 which communicates with the some cylinder bore 106 is formed. The crank chamber 108 includes a rotor 109 fixed to the outer circumference of the drive shaft 103, a sleeve 110 disposed axially movable on the outer circumference of the drive shaft 103, and an outer circumference of the sleeve 110. The journal 112 which is arrange | positioned at the side and connected to the rotor 109 through the connection link 111, and the inclination plate 113 fixed to the outer periphery of the journal 112 are provided, respectively. Each piston 107 is coupled to the outer peripheral portion of the inclined plate 113 through a pair of shoes 114. First and second springs S1 and S2 are disposed at both ends of the sleeve 110, respectively, and the inclined plate 113 after the operation stops due to the balance of the spring forces of the first and second springs S1 and S2. This initial drive position is returned.

When the drive shaft 103 rotates, each piston 107 reciprocates in the cylinder bore 106 by the rotor 109, the inclination plate 113, etc., and the inclination angle of the inclination plate 113 of each piston 107 The reciprocating stroke is variable.

The suction chamber 120 and the discharge chamber 121 are respectively formed in the rear head 101c.

The valve plate 102 interposed between the cylinder block 101a and the rear head 101c partitions between the plurality of cylinder bores 106, the suction chamber 120, and the discharge chamber 121.

In the above configuration, when the drive shaft 103 is driven to rotate, the inclined plate 113 swings, and each piston 107 reciprocates. In the suction stroke of each piston 107, a refrigerant is supplied from the suction chamber 120 into the cylinder bore 106, and the supplied refrigerant is compressed in the compression stroke of the piston 107 and discharged to the discharge chamber 121. The discharged refrigerant is circulated through the refrigerating cycle, is provided to the cooling, and is returned to the variable capacity compressor 100 again.

At the time of driving such a variable displacement compressor 100, when the heat load of the refrigeration cycle increases, the pressure of the crank chamber 108 is adjusted to the low pressure side. Then, the counterclockwise moment (the moment which moves the inclination plate 113 in FIG. 5) by the crank seal pressure which is the back pressure of each piston 107, and the spring force of the 1st spring S1, and the front of each piston 107 The balance of the clockwise moment due to the surface pressure and the spring force of the second spring S2 is broken, so that the clockwise moment in the direction of increasing the inclination angle of the inclined plate 113 becomes large, and the moment is balanced between both moments. 111 rotates in the direction of the arrow a in FIG. 5 (the second rotation support point 11b moves in the direction of the arrow from the low discharge capacity state (FIG. 7) to the large discharge capacity state (FIG. 5)). The inclination angle of the inclination plate 113 becomes large by the rotation of this connecting link 111. When the inclination angle of the inclination plate 113 becomes large, the reciprocating stroke of each piston 107 becomes large, the discharge capacity of a refrigerant | coolant becomes large, cooling ability, etc. become large.

In addition, when the heat load of the refrigerating cycle is reduced, the pressure of the crank chamber 108 is adjusted to the high pressure side. Then, the counterclockwise moment by the crank seal pressure which is the back pressure of each piston 107, and the spring force of the 1st spring S1, the front surface pressure of each piston 107, and the spring force of the 2nd spring S2 The balance of the clockwise moment is broken, the counterclockwise moment in the direction of decreasing the inclination angle of the inclined plate 113 increases, and the connecting link 111 rotates in the direction of the arrow b in FIG. 5 to a position where both moments are balanced. (The second rotary support point 11b moves in the direction of the b arrow from the large discharge capacity state (FIG. 5) to the low discharge capacity state (FIG. 7).) The inclination angle of the inclination plate 113 becomes small by the rotation of this connecting link 111. When the inclination angle of the inclination plate 113 becomes small, the reciprocating stroke of each piston 107 becomes small, the discharge capacity of a refrigerant | coolant becomes small, and cooling ability etc. become small. The variable capacity compressor 100 can reduce energy by such an operation.

In addition, in the conventional variable displacement compressor 100, as shown in Figs. 6A and 6B, the rotor 109 and the journal 112 are connected via a connecting link 111. The connection structure using the connection link 111 as described above has an advantage that the sliding resistance can be suppressed smaller than that of the guide long hole and the connection structure in which the connecting pin slides in the long guide hole.

[Patent Document 1] Japanese Patent Application Publication No. 2006-233855

However, in the variable displacement compressor 100 of the conventional example, the first rotary support point 111a to which the rotor 109 and the connection link 111 are connected, and the journal 112 and the connection link 111 are connected to each other. As for the 2nd rotation support part 111b, the 1st rotation support part 111a is set in the rotor 109 side, and the 2nd rotation support point part 111b is set in the journal 112 side. Therefore, as shown in FIG. 7, the head gap tends to be represented by the characteristic line of the conventional example of FIG. 4 at a position where the inclination angle of the inclined plate 113 is small (low discharge capacity region of the piston 107). do. And since the head gap becomes the direction of increasing as the head is directed toward the minimum capacity, and the stroke is naturally small, the ratio of the dead volume to the discharge capacity is rapidly increased, and suddenly from the cylinder bore 106 at an arbitrary inclined plate angle. A phenomenon in which the discharge flow rate of abruptly disappears occurs. Since the low discharge capacity region is originally an unstable region with a small discharge flow rate, there is a problem in that the inclination angle of the inclined plate 113 cannot be stably maintained when the discharge flow rate changes abruptly.

Therefore, an object of the present invention is to provide a variable capacity compressor capable of preventing the discharge flow rate suddenly disappearing in the low discharge capacity region as much as possible and stably maintaining the inclination angle of the inclined plate.

According to the invention of claim 1 which achieves the above object, a plurality of cylinder bores and a crank chamber communicating therewith are installed in the housing, the housing being rotatably installed so as to penetrate the crank chamber, and the rotor being provided in the driving shaft. A plurality of fixed links, a connecting link connecting the rotor and the journal, an inclined plate having a variable inclination angle by rotation of the journal, and a plurality of reciprocating movements in the plurality of cylinder bores by oscillation of the inclined plate A variable displacement compressor in which a piston is installed, the connecting link rotates about the rotor, and the inclination angle of the inclination plate is changed by this rotation, and the reciprocating stroke of each piston is variable in accordance with the inclination angle of the inclination plate. Wherein the connecting link is at a first pivotal support to the rotor and at a second pivot to the journal Each connection point in unit being characterized in that so that the head gap smaller toward the minimum capacity according to the first rotation supporting point portion and the second rotation supporting point positions set in the low portion of each discharge displacement region of the piston.

According to the invention of claim 1, in the low discharge capacity region of the piston, the head gap decreases toward the minimum capacity, so that a phenomenon in which the discharge flow rate of the refrigerant suddenly disappears in the low discharge capacity region can be prevented to the maximum, and the inclined plate The inclination angle of can be kept stable.

Invention of Claim 2 is the variable displacement compressor of Claim 1, The said connection link makes ratio of the stroke ratio (B / A) to the head clearance B of the top dead center of the said piston with respect to the stroke (A) of the said piston. In this case, the respective positions of the first rotation support point portion and the second rotation support point portion are set such that the stroke ratio in the low discharge capacity region of the piston decreases with a constant or decrease in capacity.

According to the invention of claim 2, since the stroke ratio in the low discharge capacity region of the piston decreases with a constant or decrease in capacity, the phenomenon that the discharge flow rate of the refrigerant suddenly disappears in the low discharge capacity region can be reliably prevented, and the inclined plate The inclination angle of can be kept stable.

The invention according to claim 3 is the variable displacement compressor according to claim 1 or 2, wherein the connecting link includes the first rotational support portion from the second rotational support portion to the journal side, and the second rotational support portion is the first rotational support point. It is located in the said rotor side from a part.

According to the invention of claim 3, as in the invention of claim 1, in the low discharge capacity region of the piston, since the head gap decreases toward the minimum capacity, the discharge flow rate of the refrigerant suddenly disappears in the low discharge capacity region. It can prevent as much as possible and can keep the inclination angle of the inclination plate stable.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described based on drawing.

As shown in FIG. 1, the variable displacement compressor 1 has a housing 2. The housing 2 is arranged through the cylinder block 2a, the front head 2b disposed on one side of the cylinder block 2a, and the valve body 3 on the other side of the cylinder block 2a. The rear head 2c is assembled by attaching.

In the cylinder block 2a and the front head 2b, the drive shaft 4 is arrange | positioned so that the crank chamber 10 mentioned below may pass. Both end sides of the drive shaft 4 are rotatably supported by the cylinder block 2a and the front head 2b via the radial bearing portions 5 and 6. As for the drive shaft 4, the one end side protrudes out from the front head 2b, and the pulley 7 which receives rotation of an engine is fixed to this protruding part. The drive shaft 4 is configured to rotate by receiving a driving force from the pulley 7 fixed to one end side in this way.

A plurality of cylinder bores 8 are formed in the cylinder block 2a. The plurality of cylinder bores 8 are formed at equal intervals on the circumference around the drive shaft 4. In each cylinder bore 8, the piston 9 is arrange | positioned so that sliding is possible.

The crank chamber 10 which communicates with the some cylinder bore 8 is formed in the front head 2b. The crank chamber 10 includes a rotor 11 fixed to the outer circumference of the drive shaft 4, a sleeve 12 disposed axially movable on the outer circumference of the drive shaft 4, and an outer circumferential side of the sleeve 12. The journal 13 arranged, the connection link 14 which connects the journal 13 and the rotor 11, the inclined plate 15 fixed to the outer periphery of the journal 13, and the outer peripheral part of this inclined plate 15 The rear end side of each piston 9 coupled through the pair of shoes 16 is provided.

The outer circumferential surface of the sleeve 12 is formed in a substantially arc shape, and guides the journal 13 to smoothly vary the inclination angle. First and second springs S1 and S2 are disposed at both ends of the sleeve 12, and the inclined plate 15 is stopped after operation stop due to the balance of the spring force of the first and second springs S1 and S2. The initial drive position is returned. The connection structure of the connection link 14 is explained in full detail below.

When the drive shaft 4 rotates, rotation is transmitted to the inclined plate 15 by the rotor 11, the connecting link 14 and the journal 13, so that each piston 9 reciprocates in the cylinder bore 8. do. Moreover, the stroke of each piston 9 changes with the inclination angle of the inclination plate 15, and the discharge capacity of a refrigerant | coolant changes. The mechanism by which the inclination angle of the inclination plate 15 is adjusted is demonstrated at an action site | part.

A suction chamber 20 and a discharge chamber 21 of refrigerant gas are formed in the rear head 2c. The suction chamber 20 is connected to the outlet side of the evaporator of a refrigerating cycle. The discharge chamber 21 is connected to the inlet side of the condenser of the refrigerating cycle. In addition, the suction chamber 20 and the discharge chamber 21 are partitioned by the valve body 3 in each cylinder bore 8. In the site | part of the valve body 3 which divides both chambers, the suction hole (not shown) with a suction valve, and the discharge hole 22 with a discharge valve are formed, respectively.

In addition, a bleeding passage (not shown) is always formed between the crank chamber 10 and the suction chamber 20. An air supply passage 23 is formed between the crank chamber 10 and the discharge chamber 21. The pressure control valve 24 is disposed in the air supply passage 23. It is comprised so that the pressure of the crank chamber 10 can be adjusted by controlling the opening degree of the pressure control valve 24.

Next, the connection structure of the connection link 14 is demonstrated. As shown in Figs. 1, 2A and 2B, the connecting link 14 is connected to the rotor 11 at the first rotational support portion 14a and at the journal 13 at the second rotational support portion 14b, respectively. Although the 1st rotation support part 14a is set in the journal 13 side, the 2nd rotation support point part 14b is set in the rotor 11 side. That is, the position of the 1st rotation support point part 14a and the 2nd rotation support point part 14b is connected in reverse with respect to the conventional example. By setting it as such a connection structure, as shown by the characteristic line of this invention of FIG. 4, in the low discharge capacity area | region (40% or less of capacity | capacitance, the inclination plate inclination angle 8 degrees or less) of piston 9, minimum capacity (minimum) Head gap becomes smaller as the angle of inclination increases.

In this embodiment, the degree of reduction of the head gap is determined by the ratio of the head gap B of the top dead center of the piston 9 to the stroke A of the piston 9 as shown in FIGS. 3A and 3B. If the stroke ratio B / A, the stroke ratio in the low discharge capacity region of the piston 9 is reduced in accordance with the constant or the capacity decrease, so that the first rotation support point portion 14a and the second rotation support point portion 14b Each position is set.

In the above configuration, when the drive shaft 4 rotates, the inclined plate 15 rotates by this rotational force, and the plurality of pistons 9 reciprocate in the cylinder bore 8. In the suction stroke (stroke moving from the top dead center to the bottom dead center) of the piston 9, the suction hole (not shown) is opened by the pressure reduction in the cylinder bore 8. As a result, the refrigerant gas is supplied from the suction chamber 20 to the cylinder bore 8.

In the compression stroke (stroke moving from the bottom dead center to the top dead center) of the piston 9, the suction hole (not shown) is closed, and the refrigerant gas in the cylinder bore 8 is adiabaticly compressed by the piston 9. The compressed high temperature and high pressure refrigerant gas is discharged from the discharge hole 22 to the discharge chamber 21. The high temperature and high pressure refrigerant discharged to the discharge chamber 21 is discharged out of the variable capacity compressor 1 from a discharge port (not shown). The discharged refrigerant is circulated through the refrigerating cycle and provided to cooling or the like, and returned to the variable capacity compressor 1 again.

At the time of driving such a variable capacity compressor 1, when the heat load of the refrigerating cycle becomes large, the pressure of the crank chamber 10 is adjusted to the low pressure side. Then, the counterclockwise moment (the moment which moves the inclined plate 15 in FIG. 1) by the crank seal pressure which is the back pressure of each piston 9, and the spring force of the 1st spring S1, and the front of each piston 9, The balance of the clockwise moment due to the surface pressure and the spring force of the second spring S2 is broken, so that the clockwise moment in the direction of increasing the inclination angle of the inclined plate 15 becomes large, and both moments are balanced. (14) rotates in the direction of the arrow a in Figs. 1 and 2B (the second rotational support point 14b moves in the direction of the arrow from the low discharge capacity state to the large discharge capacity state (Fig. 1). In Fig. 1, the second rotational support point 14b has already moved to the limit of the a arrow direction. The inclination angle of the inclination plate 15 increases by the rotation of this connecting link 14. When the inclination angle of the inclined plate 15 is increased, the reciprocating stroke of each piston 9 is increased, the discharge capacity of the refrigerant is increased, and the cooling ability is increased.

Moreover, when the heat load of a refrigerating cycle becomes small, the pressure of the crank chamber 10 is adjusted to the high pressure side. Then, the counterclockwise moment by the crank seal pressure which is the back pressure of each piston 9, and the spring force of the 1st spring S1, the front surface pressure of each piston 9, and the spring force of the 2nd spring S2 The counterclockwise moment is broken, the counterclockwise moment in the direction of decreasing the inclination angle of the inclined plate 15 is increased, and the connecting link 14 is moved to the position where both moments are balanced, and the arrow b in FIGS. 1 and 2B is used. Direction (the second rotation support point 14b moves in the direction of the b arrow from the large discharge capacity state (Fig. 1) to the low discharge capacity state). The inclination angle of the inclination plate 15 becomes small by the rotation of this connecting link 14. When the inclination angle of the inclined plate 15 decreases, the reciprocating stroke of each piston 9 decreases, the discharge capacity of the refrigerant decreases, and the cooling capacity and the like decrease. The variable capacity compressor 1 can save power by such an operation.

Next, the operation in the low discharge capacity region of the piston 9 will be described. In the low discharge capacity region of the piston 9, the head gap becomes smaller as it goes toward the minimum capacity (minimum inclination angle), so that a phenomenon in which the discharge flow rate of the refrigerant disappears can be reliably prevented, The inclination angle can be kept stable.

In this embodiment, since each position of the 1st rotation support point part 14a and the 2nd rotation support point part 14b is set so that the stroke ratio in the low discharge capacity area | region of the piston 9 may decrease with a fixed or capacity | capacitance fall, The phenomenon in which the discharge flow rate of the refrigerant suddenly disappears in the low discharge capacity region can be reliably prevented, and the inclination angle of the inclined plate 15 can be kept stable. That is, as shown in Figs. 3A and 3B, since the stroke ratio is large in the medium discharge capacity region, even if the head gap B is somewhat large, the influence on the stroke ratio is small. However, in the low discharge capacity region, since the stroke ratio A is small, the change in the head gap B greatly affects the stroke ratio. For this reason, in the low discharge capacity region, a phenomenon in which the refrigerant is not suddenly discharged occurs when the stroke ratio becomes large. However, the phenomenon that the refrigerant is not suddenly discharged can be prevented because the stroke ratio is set to a predetermined value or less.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows an embodiment of the present invention, and a full sectional view of a variable displacement compressor.

2A and 2B show an embodiment of the present invention, Fig. 2A is a schematic plan view showing the connection state of the connection link, and Fig. 2B is a schematic side view showing the connection state of the connection link.

3A and 3B show an embodiment of the present invention and illustrate a stroke ratio.

Fig. 4 shows an embodiment of the present invention, and shows a characteristic line showing the relationship between the discharge capacity and the head gap.

Fig. 5 is an overall sectional view of a variable displacement compressor of the prior art.

Fig. 6A is a schematic plan view showing a connection state of a connection link of a conventional example, and Fig. 6B is a schematic side view showing a connection state of a connection link of a conventional example.

Fig. 7 is a cross sectional view of a main part of the destroke.

<Explanation of symbols for the main parts of the drawings>

1: variable capacity compressor

2: housing

3: valve body

4: drive shaft

5, 6: radial bearing part

7: pulley

8: cylinder bore

9: piston

10: crankcase

11: rotor

12: sleeve

13: journal

14: Link Link

15: inclined plate

Claims (3)

A plurality of cylinder bores 8 and a crank chamber 10 communicating with the cylinder bore 8 are installed in the housing 2, and a drive shaft 4 is rotatably installed in the housing 2, and a rotor () is mounted on the drive shaft 4. 11 is fixed, and a connecting link 14 for connecting the rotor 11 and the journal 13 is installed, and an inclined plate 15 having a variable inclination angle by the rotation of the journal 13 is provided. A plurality of pistons 9 for reciprocating the plurality of cylinder bores 8 are provided by swinging the inclined plate 15, The connecting link 14 rotates around the rotor 11, and the inclination angle of the inclined plate 15 is changed by the rotation, and the respective pistons 9 are in accordance with the inclination angle of the inclined plate 15. In the variable displacement compressor (1) in which the reciprocating stroke of The connecting links 14 are respectively connected to the rotor 11 at the first rotary support points 14a, to the journal 13 at the second rotary support points 14b, and to the low discharge of the piston 9. Variable capacity compressor, characterized in that each position of the first rotation support point portion (14a) and the second rotation support point portion (14b) is set so that the head gap becomes smaller in the capacity region toward the minimum capacity. The ratio of the connection link 14 to the head clearance B of the top dead center of the piston 9 with respect to the stroke A of the piston is a stroke ratio B / A. The respective positions of the first rotary support point portion 14a and the second rotary support point portion 14b are set so that the stroke ratio in the low discharge capacity region of the piston 9 decreases with a constant or decrease in capacity. Variable capacity compressor. 3. The second rotation support point portion according to claim 1, wherein the connecting link 14 has the first rotation support point 14a closer to the journal 13 side than the second rotation support point 14b. 14. A variable displacement compressor characterized by being located at the rotor (11) side rather than the first rotary support point (14a).

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