JP4855118B2 - Variable capacity compressor - Google Patents

Description

  The present invention relates to a piston type variable displacement compressor used in, for example, a vehicle air conditioner, and more particularly to a swash plate type variable displacement compressor.

  2. Description of the Related Art Conventionally, a vehicular air conditioning compressor or the like has a swash plate cam mechanism for converting the rotational power of a main shaft into a reciprocating motion of a piston, and the reciprocating motion of the piston by changing the inclination angle of the swash plate cam mechanism 2. Description of the Related Art A variable capacity compressor that changes the stroke amount is known. In this type of compressor, while the center of the swash plate cam is slidably supported with respect to the drive shaft, the inclination angle of the swash plate is changed while sliding the swash plate on the drive shaft by the guidance of the hinge mechanism. By doing so, the stroke amount of the piston is changed, and as a result, the discharge capacity of the compressor is changed.

  As a typical center support mechanism of the swash plate, a saddle-shaped center support mechanism is representative of a hinge mechanism, and a pin is provided on one side of the hinge member and a long hole is formed on the other side. A long-hole hinge mechanism linked to each other is often used.

  However, in the vertical center support mechanism, the sliding frictional resistance between the center of the swash plate (periphery of the through hole formed in the center) and the main shaft which is the drive shaft, and the long hole hinge mechanism, the long hole The sliding frictional resistance for sliding the pin inside is large. If the frictional resistance of the swash plate center support mechanism and the hinge mechanism is large, the resistance when changing the inclination angle of the swash plate is large, and the smooth angle change is hindered and the capacity controllability of the compressor is deteriorated. It was a factor. Also, other types of hinge mechanisms and center support mechanisms have a problem of frictional resistance.

  This is not a serious problem when compressing a refrigerant having a characteristic that the high pressure side such as R134a that is currently used can condense under normal use conditions. As a countermeasure against this, when compressing a refrigerant whose cycle operation has risen to the supercritical range, such as a carbon dioxide refrigerant that has emerged as a countermeasure, the fluctuation on the high-pressure side becomes large, so smoother capacity controllability is required. It is getting to be.

  In response to such demands, Patent Document 1 discloses that in a swash plate type compressor, the center support of the swash plate is omitted, and both sides of the swash plate are joined by a link of two joints so that the swash plate can be inclined smoothly. A structure that enables angle control has been proposed.

Further, for example, a swash plate type variable capacitor, which is still in an unpublished stage of application, but is further improved from the structure described in Patent Document 1 for the purpose of simplifying the structure, saving space, improving the capacity variable control response, and the like. A mold compressor has been previously proposed by the present applicant (Patent Document 2). In this Patent Document 2, two link mechanisms are configured by providing arms on the disk surface of the rotor integrally coupled to the main shaft and on one surface facing the rotor of the swash plate, and the swash plate serves as a guide for the link mechanism. We proposed a mechanism that can change the stroke of the piston smoothly by changing the tilt angle.
German published patent DE 10 2004 028 747 A1 Japanese Patent Application No. 2006-35162

However, in the conventional variable capacity compressor, for example, as shown in FIG. 5, a swing plate 72 is connected to the swash plate 71 so as to be rotatable, and the swing plate 72 is prevented from rotating by the rotation blocking means 73. Thus, in the case of a mechanism that receives only the swing component from the swash plate 71 and reciprocates the piston 74 connected to the swing plate 72 (hereinafter referred to as “swing plate type”), the swash plate 71 and the swing plate The center of gravity 75 of the entire movable part on the swash plate 71 such as 72 and bearings is inevitably heavy on the swash plate 71 side, so it is difficult to bring it to the swing center of the swing plate 72. The center of gravity 75 has to be positioned near the swash plate of the central axis 76. In FIG. 5, the center 77 of the swash plate 71 exists at a point that coincides with the central axis 79 of the main shaft 78. As shown in FIG. 5, when the position of the center of gravity is deviated by L from the center of swing, when the inclination angle of the swash plate is α, the center of gravity is eccentric by Lsinα, and an unbalanced inertia force of f = mω ² Lsinα is generated. . Where m is the total equivalent mass of the swash plate and the swing plate, and ω is the rotational angular velocity of the main shaft 78.

  This unbalanced inertial force is caused to rotate around the main shaft 78, causing harmful vibrations. In order to improve this, for example, by providing a balance mass so as to sandwich the oscillating plate 72 connected to the swash plate 71, the value of L is reduced by bringing the position of the center of gravity 75 closer to the oscillating center side, and unbalanced inertia. Although the force is also reduced, in this case, the balance mass provided in the limited space is limited, so the center of gravity position cannot be shifted sufficiently. There were problems such as reduced reliability. For this reason, the unbalanced inertial force had to be compromised.

  On the other hand, in the structure in which the angle change of the swash plate is guided using two link mechanisms as in the above-mentioned Patent Document 2, for example, as shown in FIG. 6 (swing plate type) and FIG. 7 (single swash plate type). As described above, when the inclination angle of the swash plates 82, 92 with respect to the central axes 82, 92 of the main shafts 81, 91 is α, the swash plates 82, 92 and the swash plates 82, 92 such as the swing plate 83 and bearings are movable. The amount of eccentricity of the center of gravity 84, 93 of the entire part is Lsinα. In the structure shown in FIGS. 6 and 7, the center positions of the swash plates 82 and 92 are changed with the change in the inclination angle of the swash plates 82 and 92 because of the combination of the two link mechanisms 85, 86 and 94, 95. Is accompanied by the property of slightly deviating from the central axis 82 and 92 of the main axis. For this reason, the unbalanced inertial force described above may possibly be further increased due to the eccentricity of the link mechanism. The compressor structure that guides the angle change of the swash plate using two link mechanisms will be described in detail in the section of the embodiment of the present invention described later.

  Therefore, the present invention aims to reduce the unbalanced inertial force that causes vibration in a mechanism in which the motion center and the rotation center such as a swing plate type are easily shifted, and for a swash plate that changes the tilt angle, An object of the present invention is to reduce the unbalanced inertia force caused by the eccentricity of the center position of the swash plate generated in the structure in which the position of the swash plate is guided by the link mechanism.

In order to solve the above problems, a variable displacement compressor according to the present invention has a plurality of pistons arranged in parallel to a main shaft rotated by a driving source, and converts the rotational motion of the main shaft into reciprocating motion of the piston. A variable displacement compressor that changes the stroke amount of the piston by connecting a swash plate to the main shaft side via a plurality of link mechanisms and changing the tilt angle of the swash plate via a guide of the link mechanism In order to reduce the unbalanced inertia force generated by the eccentricity of the total center of gravity of the swash plate and the movable parts mounted on the swash plate with respect to the central axis of the main shaft , the inclination angle of the swash plate is from the maximum state to the minimum state. the value links and associated in the link mechanism so that the opposite direction to the direction of the ± directions of the eccentric with respect to spindle center axis of the radial center position of the swash plate relative to the spindle center axis line when taking between Consisting of those is characterized in that setting the size of the goods.

  This variable capacity compressor employs a structure in which the plurality of link mechanisms are arranged on the same surface side of the swash plate with respect to the swash plate as shown in FIGS. Can do. As a more specific form, for example, a rotor member is provided on the main shaft so as to be able to rotate integrally. A first link mechanism connected between a first rotor side connecting portion of the rotor member and a first swash plate side connecting portion of the swash plate; and a second link being a second rotor of the rotor member A second link mechanism connected between the side connecting portion and the second swash plate side connecting portion of the swash plate and provided on the same swash plate surface side as the first link mechanism with respect to the swash plate; It is possible to adopt a structure including.

  Alternatively, the present invention can also be applied to a variable capacity compressor having a structure in which the plurality of link mechanisms are respectively arranged on different surfaces of the swash plate with respect to the swash plate.

  In such a variable displacement compressor according to the present invention, it is also possible to take the form of a swing plate compressor. That is, a swinging plate is rotatably connected to the swash plate, and the swinging plate receives rotation components only from the swash plate by being prevented from rotating by rotation preventing means, and is connected to the swinging plate. It is also possible to provide a variable displacement compressor characterized in that the piston is reciprocated.

  Further, in the variable capacity compressor according to the present invention, basically, the center portion of the swash plate has a structure in which a hole extending through the main shaft in a non-contact state is formed. In order to prevent backlash of the swash plate or the like, a structure may be provided in which an auxiliary support member for supporting the swash plate with respect to the main shaft is provided at a position in the hole.

  Such a variable capacity compressor according to the present invention is suitable as, for example, a compressor used in a vehicle air conditioner. Further, the compressor is suitable as a compressor used for compressing a fluid to be compressed (for example, carbon dioxide refrigerant) operating in a supercritical region.

As described above, in the present invention, in order to reduce the unbalanced inertia force generated by the eccentricity of the total center of gravity of the swash plate and the movable parts mounted on the swash plate with respect to the central axis of the main shaft, the inclination angle of the swash plate is in the maximum state. Additional balance by setting the dimensions of the link and related parts so that the direction of eccentricity with respect to the main axis of the radial center position of the swash plate in the range from ± to the minimum state is reversed in the direction of ± Without increasing the number of elements and space, it is possible to realize a variable displacement compressor with low inertial imbalance, low vibration, high reliability and low cost. Further, it is possible to reduce the unbalanced inertia force due to the eccentricity with respect to the main shaft at the center of the swash plate generated in the structure in which the position of the swash plate is guided only by a plurality of link mechanisms.

  In addition, since the inclination angle of the swash plate is changed through the guidance of a link mechanism that operates smoothly, frequent pressure fluctuations on the high-pressure side, especially in systems using refrigerants operating in the supercritical region such as carbon dioxide. It is possible to realize a compressor that can be controlled without delay.

  Further, since the space around the center of the swash plate is not sacrificed, the present invention can be applied to a compression mechanism that requires a center space such as a swing plate type without any problem.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the following description, the description of the compression operation and the capacity adjustment operation will be omitted, and the description will focus on the structure of the swash plate support that is the subject of the present invention.

  1 and 2 show a variable displacement compressor 100 according to an embodiment of the present invention, and particularly show an example in which the present invention is applied to a swing plate compressor. 1 shows the state of the piston at the maximum stroke (maximum discharge capacity: maximum swash plate inclination angle), and FIG. 2 shows a partial longitudinal section of the compressor of FIG. Show. In the figure, a rotor 2 is integrally joined to a main shaft 1 as a drive shaft driven by an external drive source (not shown), and the rotor 2 rotates together with the main shaft 1. The rotor 2 is provided with an arm 3 as a first rotor side connecting portion, and one end of a link plate 4 as a first link is rotatably connected to the arm 3 via a connecting pin 5. . The other end of the link plate 4 is rotatably connected to an arm 6 as a first swash plate side connecting portion joined to the swash plate 7 via a connecting pin 8. The arm 3, the connecting pin 5, the link plate 4, the connecting pin 8, and the arm 6 constitute a first link mechanism 9. As shown in FIG. 1, the first link mechanism 9 is disposed at a position on the top dead center side of the swash plate 7.

  An arm 10 as a second swash plate side connecting portion is joined to the same side of the swash plate 7 where the first link mechanism 9 is provided, and a link plate as a second link. One end of 11 is rotatably connected via a connecting pin 12. The other end of the link plate 11 is rotatably connected to an arm 13 as a second rotor side connecting portion provided on the rotor 2 via a connecting pin 14. The arm 13, the connecting pin 14, the link plate 11, the connecting pin 12, and the arm 10 constitute a second link mechanism 15.

  An escape hole 16 is formed in the center of the swash plate 7 with respect to the main shaft 1 so that the swash plate 7 and the main shaft 1 do not contact each other. With this non-contact configuration, there is no frictional resistance at the center support. Thus, although a support member is basically not provided between the swash plate 7 and the main shaft 1 in the swash plate center, an auxiliary support member can be provided to prevent backlash between them. is there. For example, an auxiliary support member 17 as in FIG. 2 can be provided.

  The rotational oscillating motion of the swash plate 7 is transmitted to the oscillating plate 20 through the bearings 18 and 19, and the oscillating plate 20 is prevented from rotating by the rotation preventing mechanism 21 and performs only the oscillating motion. It is like that. A piston 23 is ball-connected to the swing plate 20 via a rod 22, and the piston 23 is reciprocated via the rod 22.

  1 and 2 show an example of a swing plate compressor, and a so-called axial plunger method in which the rod 22 in the figure is omitted is also included in the swing plate compressor as an application object of the present invention. .

  In the variable displacement compressor 100 configured as described above, the swash plate 7 can change the inclination angle, and the rotor 2 is maintained while maintaining a relationship such that the center of the swash plate 7 substantially coincides with the center axis of the main shaft 1. Supported. However, the escape plate 16 is formed in the center of the swash plate 7 with respect to the main shaft 1 so that the swash plate center position is not determined by the main shaft. The rotational force and the compression reaction force from the piston 23 are received by the link plate 4 and the link plate 11. Thus, by adjusting the pressure of the crank chamber 24 (illustration and description of the adjusting means are omitted), the target swash plate inclination angle can be set in balance with the gas compression reaction force.

  The swash plate 7 is supported by the first link mechanism 9 and the second link mechanism 15 while being basically kept out of contact with the main shaft 1, and the swash plate inclination angle is changed in the supported state. The By maintaining the swash plate 7 and the main shaft 1 in a non-contact state, no frictional resistance is generated during this time, and the swash plate tilt angle can be changed smoothly, thereby improving controllability. Further, since the support of the swash plate center is unnecessary, a sufficient space around the swash plate center can be taken, and the cost can be reduced. In addition, since the two link mechanisms can be operated smoothly, even in a system using a refrigerant operating in the supercritical region such as carbon dioxide, the responsiveness is not delayed by frequent pressure fluctuations on the high pressure side. Excellent control is possible.

  In the first link mechanism and the second link mechanism, a pair of each connecting portion and each link can be provided. For example, as shown in FIG. 2, this portion in the above embodiment is used as an arm 6 as a first swash plate side connecting portion extending from the swash plate 7 and a first rotor side connecting portion extending from the rotor 2. Arm 3, link plate 4 serving as a first link connected to them, arm 10 serving as a second swash plate side connecting portion extending from the same surface of swash plate 7, and first extending from rotor 2. It is possible to provide a pair of arms 13 as the two rotor-side connecting portions and a pair of link plates 11 as the second links to be connected to them (that is, two at a time). It is also possible. Thus, if it arrange | positions so that a some link may be piled up in parallel, the support capability of the falling moment which generate | occur | produces in the swash plate 7 can be improved. However, each of these may be configured by one link and one connecting portion.

  The application of the present invention in the variable displacement compressor 100 as described above will be described below. In FIG. 1, the radial center 31 of the swash plate 7 is on the central axis 33 of the swash plate 7, and the swash plate 7, the swing plate 20, the bearings 18 and 19, and the link plate 4 are in the vicinity of the central axis 33. , 11 and the like, there is a total center of gravity 30 of components attached to the swash plate 7. However, the center of gravity 30 is not necessarily present on the central axis 33 due to the part shape or the like, but is displayed for convenience. The center of gravity 30 is shifted from the center axis 32 of the main shaft 1 by a distance L, and when the inclination angle of the swash plate 7 is α, Lsinα is the amount of eccentricity of the center of gravity.

When the total mass applied to the total center of gravity 30 is m and the rotational angular velocity of the main shaft is ω, an unbalanced inertia force of f = mω ² Lsinα is generated. On the other hand, the case where the present invention is not applied will be described with reference to FIGS. In FIG. 6, the same conceptual view of the mechanism as in FIG. 1 is used for ease of explanation, but this center supports the center of the swash plate 71 in FIG. 5 so as to be movable with respect to the main shaft 78 by means such as a sleeve. However, the same applies to the method of guiding the movement of the swash plate 71 with another hinge means.

  In FIGS. 5 and 6, the centers 77 and 87 of the swash plate exist at points that coincide with the central axes 79 and 82 of the main shafts 78 and 81. In the method of guiding the movement of the swash plate 71 by another hinge means while supporting the center of the swash plate movably with respect to the main shaft 78 by means such as a sleeve as shown in FIG. Supported.

  Next, the center of gravity exists at the positions 75 and 84 in FIGS. 5 and 6, and the distance from the center axis of the center of gravity is Lsinα, but the distance L in this case is longer than that in FIG. Therefore, the unbalanced inertial force f eventually becomes larger than that in the case of FIG.

  This size is determined by the center deviation amount (eccentricity) ε between the swash plate center 31 and the spindle central axis 32 in FIG. On the other hand, by appropriately setting the parameter dimensions of each link mechanism, the change characteristic curve of ε with respect to the change from the maximum value to the minimum value of the inclination angle α of the swash plate 7 can determine an arbitrary characteristic to some extent.

  As an example, FIG. 3 shows an example of the relationship between the swash plate inclination angle α and the amount of eccentricity ε between the swash plate and the spindle center axis. Note that “top” in FIG. 3 indicates the piston top dead center position.

Such a characteristic of the eccentricity ε appropriately sets the values of the dimensional parameters a, b, c, d, f, g, h, i, j, k of each part in the link mechanism as shown in FIG. Can be obtained. When the dimensions and parameters shown in FIG. 4 are used, the following calculation formula is established.
L (α) = L ₁ (α) + L ₂ (α) + L ₃ (α) + L ₄ (α)
L ₁ (α) = e · sin α
f = e ² + b ² -2eb · cos (α + β)
cos (α + β) = (e ² + b ² −f ² ) / 2eb
β = cos ⁻¹ [(e ² + b ² −f ² ) / 2eb] −α]
L ₂ (α) = b · sin β
= B · sin [cos ⁻¹ [(e ² + b ² −f ² ) / 2eb] −α]
L ₃ (α) = [c ² − (b · cos β−a + ε) ² ] ^1/2
L ₄ (α) = [g ² − (he · cos α) ² ] ^1/2
θ = cos ⁻¹ [(b ² + k ² −d ² ) / 2bk]
φ = π / 2-α-β-θ
u ₂ (α) = k · sin (β + θ)
u ₃ (α) = [j ² − (k · cos (π / 2−α−φ) + i + ε) ² ] ^1/2
δ = L ₂ (α) + L ₃ (α) −u ₂ (α) −u ₃ (α)
Here, if ε satisfying δ = 0 is obtained, the amount of eccentricity with respect to the main axis of the swash plate can be obtained. The top at that time is L at the point where δ = 0. In the above, L represents the first link side height, u represents the second link side height, and ε represents the eccentricity of + to the upper side in FIG. 4 and − to the lower side.

  Then, by intentionally setting the change characteristic of ε as shown in FIG. 3, a negative (−) value is obtained in a region where the swash plate inclination angle α is large, that is, the swash plate center 31 in FIG. As the value of L decreases and the swash plate inclination angle α decreases, the unbalanced inertial force decreases as α decreases, and the direction change of the unbalanced inertial force in the reverse direction is canceled. It is possible to obtain a characteristic of total balance inertia force in which ε decreases toward zero and ε changes in the positive (+) direction.

  For example, in the conventional design in which the center of the swash plate is forcibly moved on the center line of the main axis, when the total center of gravity is deviated from the center of the swash plate, it is large when the inclination angle of the swash plate is large. When the swash plate inclination angle becomes smaller, the amount of unbalance becomes smaller, so it is difficult to always balance the change in the swash plate inclination angle.

  Although the present invention has been described with respect to the specific example of the swing plate type mechanism, it can be similarly applied to other types of variable displacement compressors such as a so-called swash plate type (FIG. 7). That is, even in a system using other swash plates, the position deviation between the center and the center of gravity of the swash plate can occur in design, and the two other examples given here as examples using other swash plates are also described. In the case of using the method of guiding the swash plate by the link, the center of gravity of the swash plate is shifted in order to reduce the adverse effect (unbalance inertia force) due to the eccentricity generated between the center of the swash plate and the spindle center line. It is within the intended scope of the present invention to set the change characteristic of the eccentricity ε between the center of the swash plate and the center axis of the canceling shaft so that the direction with respect to the center axis of the main shaft is reversed.

  INDUSTRIAL APPLICABILITY The present invention can be applied to any variable displacement compressor having a swash plate and a plurality of link mechanisms for guiding the swash plate, and particularly as a compressor used in a vehicle air conditioner or supercritical such as carbon dioxide. It is suitable as a compressor used in a system using a refrigerant that operates in a region.

It is a longitudinal cross-sectional view which shows the state at the time of the swash plate inclination angle maximum of the variable capacity type compressor which concerns on one embodiment of this invention. It is the partial longitudinal cross-sectional view seen from the direction which differs 90 degree | times of the compressor of FIG. It is a characteristic view which shows an example of the relationship between a swash plate inclination | tilt angle, a swash plate eccentric amount, and a piston top dead center position. It is explanatory drawing showing each dimension and each parameter at the time of setting a dimension in this invention. It is a schematic longitudinal cross-sectional view which shows an example of the state of the gravity center deviation in the conventional variable capacity type compressor. It is a schematic longitudinal cross-sectional view which shows an example of the state of a gravity center shift | offset | difference at the time of not applying this invention in the variable capacity type compressor which the present applicant previously proposed. It is a schematic longitudinal cross-sectional view which shows an example of the state of a gravity center shift | offset | difference at the time of not applying this invention in another variable capacity type compressor which the present applicant previously proposed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main axis | shaft 2 Rotor 3 Arm 4 as 1st rotor side connection part Link board 5, 8 as 1st link Connection pin 6 Arm 7 as 1st swash plate side connection part Swash plate 9 1st link mechanism DESCRIPTION OF SYMBOLS 10 Arm 11 as 2nd swash plate side connection part Link board 12, 14 as 2nd link Connection pin 13 Arm 15 as 2nd rotor side connection part 2nd link mechanism 16 Escape hole 17 Auxiliary support Members 18 and 19 Bearing 20 Oscillating plate 21 Anti-rotation mechanism 22 Rod 23 Piston 24 Crank chamber 30 Total center of gravity 31 Swash plate center 32 Main shaft center axis 33 Swash plate center axis 100 Variable capacity compressor ε Eccentricity

Claims (8)

A plurality of pistons are arranged in parallel to the main shaft rotated by the drive source, and a swash plate for converting the rotational movement of the main shaft into the reciprocating motion of the piston is connected to the main shaft side via a plurality of link mechanisms. In the variable capacity compressor that changes the stroke amount of the piston by changing the inclination angle of the swash plate through the guide of the link mechanism, the total center of gravity of the swash plate and the movable parts mounted on the swash plate In order to reduce the unbalanced inertia force generated by the eccentricity with respect to the main shaft center axis, the main shaft center axis of the radial center position of the swash plate when the inclination angle of the swash plate takes a value between the maximum state and the minimum state The variable capacity compressor characterized in that the dimensions of the link and related parts in the link mechanism are set so that the direction of eccentricity with respect to the axis is opposite to the direction of ± with respect to the central axis of the main shaft .   The variable capacity compressor according to claim 1, wherein the plurality of link mechanisms are arranged on the same surface side of the swash plate with respect to the swash plate.   A rotor member is provided on the main shaft so as to be integrally rotatable, and the plurality of link mechanisms are configured such that the first link is located on the first rotor side of the rotor member at a position on the swash plate top dead center side when viewed from the center line of the main shaft. A first link mechanism connected between the connecting portion and the first swash plate side connecting portion of the swash plate; and a second link of the second rotor side connecting portion of the rotor member and the first swash plate side connecting portion. 2. A second link mechanism connected between two swash plate side connecting portions and provided on the same swash plate surface side as the first link mechanism with respect to the swash plate. 2. The variable capacity compressor according to 2.   2. The variable capacity compressor according to claim 1, wherein the plurality of link mechanisms are respectively disposed on different surfaces of the swash plate with respect to the swash plate.   A oscillating plate is rotatably connected to the swash plate, and the oscillating plate is prevented from rotating by rotation preventing means, so that only a oscillating component is received from the swash plate, and a piston connected to the oscillating plate is connected. The variable capacity compressor according to claim 1, wherein the compressor is reciprocated.   The variable capacity compressor according to claim 1, wherein a hole extending through the main shaft in a non-contact state is formed in a central portion of the swash plate.   The variable capacity compressor according to claim 1, comprising a compressor used for a vehicle air conditioner.   The variable capacity compressor according to claim 1, comprising a compressor used for compressing a fluid to be compressed that operates in a supercritical region.

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