JP3259708B2 - Scroll type variable capacity compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type variable displacement compressor suitable for use as, for example, a refrigerant compressor for a car air conditioner, and more particularly to a variable displacement mechanism of a scroll type compressor.

[0002]

2. Description of the Related Art A variable mechanism of a conventional scroll type compressor has a fixed scroll member having a bypass hole opened and a bypass hole opened and closed by a plunger as described in, for example, Japanese Patent Application Laid-Open No. 3-237285. I was trying to do it.

[0003] The shape of the bypass hole has been circular or oval.

[0004]

The bypass hole delays the start of compression by returning the fluid in the working space during compression to the suction pressure chamber side, so that the fluid flows when the fluid passes through the bypass hole. Resistance needs to be minimized. That is, if the fluid causes a large pressure loss when passing through the bypass hole, the pressure loss when passing through the bypass hole is large,
The fluid in the working space will not sufficiently escape to the suction pressure chamber side, and even if the bypass hole is opened, the capacity of the compressor will not be reduced to the desired capacity. That is, the compressor is driven with an unnecessarily large capacity, which hinders efficient operation of the compressor.

An object of the present invention is to solve the problem by increasing the flow passage area of the bypass hole, thereby suppressing the flow resistance when passing through the bypass hole.

[0006]

The present invention, as a means for solving the above problems, comprises a fixed scroll member having an involute blade fixed on an end plate and an involute blade fixed on an end plate. In a scroll compressor including a movable scroll member forming a plurality of working spaces with a fixed scroll member, a bypass hole communicating the working space and the suction pressure chamber is provided.
A means of forming a long hole along the shape of the involute blade of the movable scroll is adopted.

[0007]

When the movable scroll member is driven with respect to the fixed scroll member, the movable scroll member revolves without rotation, and the spiral blades of these scroll members mesh with each other to form between them. The plurality of working spaces are continuously moved from the outer peripheral portion toward the center portion, and the volume of each working space is reduced steplessly, so that the inside of each working space at the outer circumferential portion of both scroll members is reduced. As in the case of a normal scroll compressor, a gas such as a refrigerant sucked into the compressor is compressed and discharged at a high pressure at the center.

In the present invention, since the bypass hole communicating the working space and the suction pressure chamber is formed as an elongated hole that follows the shape of the involute blade of the orbiting scroll, the axial length of the bypass hole is increased, and the bypass hole is enlarged. The flow passage area of the hole can be widened.

[0009] That is, if the bypass hole is simply oval, the involute blade is formed as a curved surface,
If the long axis direction of the ellipse is large, the movable scroll member protrudes from the involute blade, and the fluid from the working space, which does not need to be bypassed, is bypassed. Therefore, the circular, oval bypass hole exit is naturally limited in its flow path area, but in the present invention, even if the axial length of the bypass hole is increased, it does not protrude from the involute blade of the movable scroll member, The flow path area can be made sufficiently large.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of a scroll type variable displacement compressor according to a first embodiment of the present invention is shown in FIGS.
In these figures, reference numeral 1 denotes a rotating shaft,
a. A front housing 2 rotatably supports the rotary shaft 1 via bearings 3 and 4. Reference numeral 5 denotes a movable scroll member.
It consists of an involute blade and an end plate formed into a 5-turn involute shape, and is rotatably incorporated with the crank portion 1a of the rotary shaft by a needle bearing 6. Further, a so-called anti-rotation mechanism is provided between the movable scroll member 5 and the front housing 2 by a combination of a plurality of spheres 7 and circular grooves. 8
Is a fixed scroll member integrally having a casing portion having a suction port 8e, and also has an involute blade and an end plate formed substantially in an involute shape of approximately 2.5 turns. Reference numeral 9 denotes a rear housing having a discharge port 9a, which is fixed together with the front housing 2 and the fixed scroll member 8 by a bolt (not shown).

As shown in FIG. 2, the bypass hole 8b according to the present embodiment has a long hole shape following the shape of the involute blade of the movable scroll member 5. In particular, the width of the long hole is perforated so as to be smaller than the blade width (thickness) of the involute blade of the movable scroll member 5.

The variable displacement mechanism includes the fixed scroll member 8.
Is incorporated in the end plate.

Numeral 10 denotes a cylindrical plunger which is slidably incorporated in a cylinder 8a provided on an end plate of the fixed scroll member, and which connects the cylinder 8a to an involute blade of the fixed and movable scroll member 5. among a plurality of operating space of the bypass hole group 8b communicating enclosed between the bypass hole 8 communicating with the working space V _a1 of the outermost nearer
b and four bypass hole 8b ₁ ~8b ₄ except ₀ are sequentially enabled blocking. Reference numeral 11 denotes a stopper bolt having a stopper portion 11a formed of a small diameter column extending into the cylinder 8a, at a position for restricting the amount of upward movement of the plunger 10 in FIGS. 1 and 2 to a predetermined amount. , And is screwed to the fixed scroll member 8a.
Numeral 12 denotes a spring which is inserted between the stopper bolt 11 and the plunger 10 to move the plunger in FIG.
2 and downward direction, that is, the bypass hole group 8
The plunger 10 is pressed toward the center position (the state shown in FIG. 1) that opens all of b. Furthermore, with the front end direction is provided a control pressure chamber V _c of the plunger 10, the high-pressure passage 8c and the intake pressure chamber V _s to communicate with the central portion of the involute vane fixed scroll member 8 and the control pressure chamber V _c The control valve 20 connected to the communicating low pressure passage 8d is incorporated.

Further, the end plate of the fixed scroll member 8 includes
Among the plurality of operating space surrounded between the fixed and the involute vane movable, and the working space V _a3 of the central portion, a discharge port communicating the discharge chamber V _d which is surrounded by the end plates of the rear housing 9 and the fixed scroll member 8 8f is provided, on the discharge port 8f, so as to close it, the discharge chamber V _d from the sheet side reed valve 13, the bolt 14
And is provided.

FIG. 2 shows the arrangement of the bypass hole group 8b. In the present embodiment, the bypass hole group 8b is 8b ₀ ~8b ₄
5 round holes, and a bypass hole 8 near the outermost periphery.
b ₀ is larger than the hole diameter of the other bypass hole 8b ₁ ~8b _4, drilled at a position that comes into contact with the inside of the outermost end of the involute vane fixed scroll member 8, most inboard bypass hole 8b ₄ of involute A hole is drilled at a position in contact with the innermost periphery of the blade. Then, between these two bypass holes, a further 8b _1, 8b _2, 3 pieces of bypass hole of 8b _3, so as not to interfere with the involute vane, and drilling at substantially equal intervals. Of these bypass hole, four hole diameter bypass hole 8b ₁ ~8b ₄ except bypass hole 8b ₀ provided in the outermost, the movable scroll member 5
Is set substantially equal to the thickness of the involute blade.

[0016] The configuration of the control valve 20 for guiding the control pressure to the control pressure chamber V _c shown in FIG. Reference numeral 21 denotes a casing having a tapered valve seat 21a, and reference numeral 22 denotes a valve body in which a spherical body 22a and a rod 22b are integrally connected. 23 is a diaphragm which is connected with the end of the rod 22b, a spring 25 providing the load due to the pressure difference between the atmospheric pressure to be introduced into the suction pressure P _s and a lower surface side which is introduced on the upper surface side, the set pressure The valve body 22 is incorporated so as to be displaced by receiving the load described above and move the valve body 22 in the vertical direction in FIG. The valve unit comprising a tapered valve seat 21a and the valve body 22. casing 21, and the control pressure P _c and the suction pressure P _s is placed between the chamber acting respectively, by receiving the displacement of the diaphragm 23 , And is configured to open and close the valve portion.

In this control valve 20, the spring 2
Biasing load of 5, when the suction pressure P _s is approximately 2 atmospheres (gauge), the diaphragm 23 is set to be equal to the load applied downward in FIG. 3, the suction pressure P _s is 2 the valve unit is a pressure (gauge) or more closed, is less than the suction pressure P _s is 2 atm (gauge) are set so that the valve unit is opened.

The pump operation of the scroll type variable displacement compressor according to this embodiment will be described first. When the rotating shaft 1 is rotated, the crank portion 1a of the rotating shaft 1
Causes the movable scroll member 5 to revolve. At this time, the sphere 7
The rotation of the orbiting scroll member 5 is prevented by the action of the rotation preventing mechanism composed of the circular grooves. Thus, a plurality of working space V _a which is surrounded by the fixed scroll member 8 and the movable scroll member 5 is moved to compress the refrigerant while reducing the volume toward the central portion from the outer peripheral portion. At this time,
Refrigerant from an evaporator outlet side of a refrigeration cycle of a car air conditioner (not shown) is supplied from a suction port 8e to a suction pressure chamber V of a compressor.
_s, and is confined in the outermost working space, is gradually moved to the center with the rotation of the rotary shaft 1 and is compressed, and finally pushes the reed valve 13 from the discharge port 8f to discharge the pressure chamber V. _It is discharged to _d, and is discharged from the discharge port 9a to the condenser inlet side of the refrigeration cycle (not shown).

Next, the operation of the variable displacement mechanism will be described. When the cooling load is required to be operated at maximum capacity large, the suction pressure P _s is the diaphragm 23 is higher than 2 atmospheres (gauge) spring 2 shown in FIG. 3
5, the valve body 22 is also lowered and the valve portion of the control valve 20 is closed. Thus, from the high pressure passage 8c which opens the involute blade central portion to the end plate direction of the movable scroll member 5 of the fixed scroll member 8, to wither Shirubebi the high pressure refrigerant pressure control chamber V _c from the working space of the central portion The control pressure chamber V _c is provided on the lower surface of the plunger 10.
Since the control pressure P _c is applied for, also on the upper surface acts suction pressure P _s, when the load corresponding to the product of those of the cross-sectional area of the differential pressure and the plunger 10 is greater than the biasing force of the spring 12 The plunger 10 moves upward in the cylinder 8a to a position where it comes into contact with the stopper portion of the stopper bolt 11,
Among the bypass hole group 8b, thereby closing the four bypass hole 8b ₁ ~8b ₄ except bypass hole 8b ₀ of the outermost peripheral portion as shown in FIG.

[0020] or when the cooling load is decreased, the rotational speed of the compressor is high, the suction pressure P _s is lowered to 2 atmospheres (gauge) or less, the diaphragm 23 and the valve body 22 shown in FIG. 3 is pressed by the spring 25 As a result, the valve portion of the control valve 20 is opened. At this time, the high pressure P _c in the control pressure chamber V _c will escape to the suction pressure P _s side through the valve portion. High pressure passage 8
Since the leading end of c communicates with the end plate of the movable scroll member 5 at a small interval to the high-pressure working space at the center, a small amount of refrigerant flowing from the high-pressure passage 8c is also controlled by the throttle effect at this minute interval. It will flow out to the side of the chamber the suction pressure P _s through the valve portion is acting in the valve 20, resulting in the control pressure chamber V
the control pressure P _c in _c will decrease.

Thereby, the plunger 10 acts.
Control pressure P_cAnd the biasing force of the spring 12
To overcome, plunger 10 moves downward in FIG.
It moves and the second bypass hole 8b from the outer periphery shown in FIG.₁
To the position to open. In this state, the bypass hole 8b
₁Working space V communicating with_aRefrigerant in the compressor
Ipass hole 8b₁Flows into the cylinder 8a from the
8b₀Through the suction pressure chamber V _sBackflow to Thereby real
Compressor capacity decreases, cooling capacity decreases, and suction pressure P
_sWill rise. And the suction pressure P_sIs 2 atm
Control), the valve portion of the control valve 20 is closed and control is performed.
Pressure P_cTo rise. As a result, the plunger 10
Close the bypass hole 8b and operate again to maximize the capacity.
You. In addition, the suction pressure Ps is kept below 2 atmospheres (gauge).
And the valve portion of the control valve 20 maintains the open state, and the control pressure P_cIs
Further decline. Thereby, the plunger 10 is further
Bypass hole 8b_TwoWill be opened, and more centrally
Close working space is bypass hole 8b_TwoTo the suction side via
As a result, the refrigerant in this working space is
Hole 8b_TwoThrough the cylinder 8a and the suction pressure chamber V_sBackflow to
However, the actual compressor capacity is further reduced.

As described above, the scroll in this embodiment is
The variable displacement compressor has a suction pressure P _sTo the control valve 20
If the pressure is higher than the set pressure 2 atm (gauge)
, The bypass hole group 8b is closed sequentially from the center.
Increase the capacity and increase the suction pressure P_sIs more than 2 atmospheres (gauge)
If it is low, the bypass hole group 8b is opened sequentially from the outer periphery.
Released to reduce capacity.

The group of bypass holes 8 shown in this embodiment
In the scroll type variable displacement compressor having b, the plunger 10 gradually opens the bypass hole from the outer periphery.
The accompanying change in compressor capacity will be described with reference to FIG. FIGS. 4A to 4F show changes in the working space for each revolution angle of the movable scroll member 5 of 60 °.

[0024] Incidentally, FIG. (A) ~ (f), since a conceptual diagram for use in operating description of the bypass hole 8b ₀ ~8b _4, the shape of the bypass hole 8b ₀ ~8b ₄ long hole according to the present invention Instead of a shape, a circle is used instead.

The bypass hole 8b ₀ of the outermost is open at all times, this portion of the bypass hole 8b ₀ from that always suction space V _s, the compressor capacity working space V ₅₀ 2 places content in this state And the capacity is 100%.

When the two bypass holes 8b ₀ and 8b ₁ are opened from the outer periphery, the compressor capacity becomes the sum of V ₅₀ and V ₃₅ shown in FIG. 4, and is approximately 85%. Because Figure 4
One of the two working spaces surrounded by the two involute vane (a), the suction space in the process of reduction to V ₃₅ shown in FIG. (D), the refrigerant in the working space from the bypass hole 8b ₁ flow back to, capacity is reduced to V _35. Then, only after that, the compression / discharge action is performed toward the center.

Further, the bypass holes 8b ₀ , 8b ₁ , 8b ₂
When but opened, the capacitor shown as working space V ₃₅ in FIG. 4 (d), the until 60% of the volume is the sum of the capacitance shown as V ₂₅ in FIG. 4 (a), the bypass hole 8b
₁ refrigerant from ～8B ₂ to the suction space is to reflux.

Similarly, when four of the bypass holes 8b _{0 to} 8b ₃ are opened, the capacity becomes 35% which is the sum of V ₂₅ shown in FIG. 4A and V ₁₀ shown in FIG. 8b
_When all of the five bypass holes _{0 to} 8b ₄ are opened, FIG.
Of 15% volume was indicated as V ₁₅ at (e).

[0029] When shown in the graph summarizes the above results, the amount of displacement of the plunger 10 on the horizontal axis, as Fig. 5 which is a compressor volume on the vertical axis, until 8b ₁ ~8b ₄ bypass hole group 8b is sequentially opening By doing so, it is possible to realize continuous capacitance changes at substantially equal intervals.

As apparent from FIGS. 4A to 4F, when the bypass hole 8b does not communicate with the working space, it must be closed by the involute blade of the movable scroll member 5. In other words, if the bypass hole 8b is larger than the involute blade of the movable scroll member 5, the working space inside the involute blade of the movable scroll member 5 communicates with the outside working space via the bypass hole 8b. Will be done. this is,
This causes internal leakage of the scroll compressor, which significantly reduces compressor performance.

Therefore, the width of the bypass hole 8b must always be set smaller than the blade width (thickness) of the involute blade of the movable scroll member 5.

Therefore, as in a conventional scroll type variable displacement compressor, if the shape of the bypass hole is circular or oval,
In order to increase the flow passage area of the bypass hole 8b, the blade thickness of the involute blade of the movable scroll member 5 must be increased, which results in an increase in the outer shape of the compressor.

On the other hand, as shown in FIG. 2, the bypass hole 8b according to the present embodiment has a long hole shape following the shape of the involute blade of the movable scroll member 5, so that the thickness of the blade of the movable scroll member 5 is increased. Without increasing
The flow passage area of the bypass hole 8b can be increased. Therefore, the passage resistance at the time of bypass is small, and the fluid to be compressed such as the refrigerant can be reliably bypassed.

If the passage resistance at the time of bypass is large, the refrigerant in the working space cannot reliably flow back to the suction space via the bypass hole 8b. That is, even if the compressor is designed to reduce the compressor capacity to the 15% capacity shown in FIG. 5 by opening all the bypass holes 8b, the capacity cannot be reduced as intended due to the passage resistance at the time of bypass of the bypass holes 8b. appear. This is particularly noticeable when the scroll compressor is rotating at a high speed, and if this is the case, the capacity variable range is narrowed.

On the other hand, in the present embodiment, as described above, the passage resistance at the time of bypass is small, and the fluid to be compressed such as the refrigerant can be bypassed without fail. Can be prevented. In particular, when the maximum suction capacity of the compressor is large, the amount of the refrigerant flowing back into the suction space via the bypass hole 8b naturally increases, and the effect of the present embodiment is great.

Further, in the present embodiment, the number of parts is reduced by adopting a simple structure in which one plunger opens and closes a group of bypass holes arranged at substantially equal pitches from the outer periphery to the center of the fixed scroll member. A substantially continuous variable displacement mechanism for a scroll compressor can be provided. Further, operation by set substantially the same four diameter of the bypass hole 8b ₁ ~8b ₄ the Atsushi Hane of the movable scroll member, in a state in which the blade has come to the position of the bypass hole, near the center across the blade Since the backflow of the refrigerant from the space to the working space near the outer periphery does not occur, the efficiency does not decrease. On the other hand, by arranging the bypass hole group at a position offset from the center of the fixed scroll member 8, the discharge port 8 f and the reed valve 13 can be arranged at the center of the fixed scroll member 8.
It has excellent assemblability.

As described above, the characteristic of the scroll type compressor, in which a plurality of working chambers are arranged on a line (on the axis of the cylinder 8a) from the vicinity of the outermost periphery of the involute blade of the fixed scroll member to the center, is utilized. The variable capacity is achieved by selectively performing bypass from among a plurality of working chambers through a group of bypass holes 8b drilled on the axis. At this time, the position of each bypass hole of the bypass hole group 8b is determined from the geometrical positional relationship between the involute blade of the fixed scroll member and the involute blade of the movable scroll member, but the axis of the cylinder 8a must be appropriately determined. Thereby, the relationship between the bypass hole position and the capacity as shown in FIG. 5 can be easily made substantially linear.

In operation of the variable mechanism of the scroll type variable displacement compressor, a control pressure is applied to the plunger 10, and the control pressure is applied from a central portion of the working space of the compressor to a small distance from the tip of the blade. High pressure control valve 20
In this way, the small interval is caused to act as a throttle, thereby limiting the supply amount of the high-pressure refrigerant. For this reason, it is not necessary to provide a special throttle portion in the high-pressure passage from the high-pressure portion to the control valve 20, and there is no possibility that the throttle portion will be blocked. Furthermore, since the pressure of the refrigerant in the high pressure section of the compressor itself is used as the control pressure, there is no need to prepare a special power source such as a motor for operating the plunger, and the scroll compressor has a simple configuration. Variable capacitance can be realized.

On the other hand, when the scroll-type variable displacement compressor according to the present embodiment stops the rotation, the pressure of the working space for supplying high pressure to the control valve 20 is blocked by the reed valve 13 with respect to the discharge chamber V _d to the suction pressure chamber and the same pressure, the control pressure also becomes the suction chamber V _s the same pressure, the plunger 10 by the force of the spring 12 acts, the plunger 10 to open all of the bypass hole 8b located Will be stopped. For this reason, at the time of restarting, all the bypass holes 8b are always in the minimum capacity state in which they are opened, the driving torque is low, and the starting shock is small. Therefore, this scroll type compressor is used as a refrigerant compressor for a car air conditioner. In such a case, the shock at the time of starting and the accompanying noise can be reduced, and the comfort of the vehicle can be further improved.

FIG. 6 shows a second embodiment in which a bypass hole group 8b is provided at a position different from that of the first embodiment shown in FIG. As is apparent from FIG.
with a first bypass hole 8b ₀ outside the entered part to about 180 ° inside the outermost peripheral position of the involute vane of b position the fixed scroll member 8 is so as to open, as shown in FIG. 7, a bypass when the opening of the hole 8b ₁ to about 9
0% to about 70% during the 8b ₂ opening, approximately at the aperture of 8b ₃ 40
%, So that the aperture at about 15% of 8b _4, be set to indicate the stepwise change in capacitance, the volume change region of the compressor, be continuous variable equal to the first embodiment Can be done.

[0041] FIG. 6 is also a schematic view for use in open position description of the bypass hole 8b ₀ ~8b _4, therefore, the shape of the bypass hole 8b ₀ ~8b ₄ is in place of the long hole shape according to the present invention,
It is shown as a circle.

The position of the bypass hole group 8b is not limited to those shown in FIGS.
A plurality of bypass holes 8b may be arranged substantially linearly from the outer peripheral portion toward the central portion. In the first and second embodiments, using suction pressure P _s and the discharge pressure P _d, but by controlling the control pressure P _c by the control valve 20, so as to electrically control using the solenoid valve You may.

[0043]

In the scroll type variable displacement compressor according to the present invention, the bypass hole is formed in the shape of an elongated hole which follows the shape of the involute blade of the movable scroll member. Therefore, the bypass hole can be formed without increasing the blade thickness of the movable scroll member. The flow passage area of the hole can be widened. Therefore, the passage resistance at the time of bypass is small, and the fluid to be compressed such as the refrigerant can be surely bypassed. As a result, it is possible to prevent the capacity variable range from being narrowed at the time of high rotation.

In the scroll type variable displacement compressor according to the second aspect of the present invention, since the width of the long hole of the bypass hole is formed narrower than the width of the involute blade of the movable scroll, the movable hole is movable through the bypass hole. The working space inside the scroll involute blade and the working space outside the scroll communicate with each other, so that there is no possibility of internal leakage of the scroll type variable displacement compressor.

In the scroll type variable displacement compressor according to the third aspect of the present invention, since the bypass holes are formed on a plurality of straight lines, the compressor is opened and closed by the plunger sequentially. Can be varied stepwise.

Further, in the scroll type variable displacement compressor according to the fourth aspect of the present invention, since the bypass hole is formed along the involute blade in the end plate of the fixed scroll at a position near the involute blade. The bypass hole can be closed by the movable scroll involute blade while the scroll involute blade is in contact with the movable scroll involute blade.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a first embodiment of the present invention.

FIG. 2 is a side view showing a fixed scroll member according to the first embodiment.

FIG. 3 is an enlarged sectional view showing a portion related to a control valve.

FIGS. 4A to 4F are side views sequentially illustrating a change in a positional relationship between both scroll members and a group of bypass holes in order to explain the operation of the compressor according to the present invention.

FIG. 5 is a diagram illustrating a change in the discharge capacity due to the sequential opening of the bypass holes according to the displacement of the plunger in the first embodiment.

FIG. 6 is a side view showing a fixed scroll member according to a second embodiment.

FIG. 7 is a diagram illustrating a change in discharge capacity due to sequential opening of bypass holes according to displacement of a plunger in the second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotating shaft 1a ... Crank part 5 ... Movable scroll member 8 ... Fixed scroll member 8a ... Cylinder 8b ... Bypass hole group 8c ... High pressure passage 8d ... Low pressure passage 8e ... Suction port 8f ... Discharge port 9a ... Discharge port 10 ... Plunger 11 ... stopper bolt 12 ... spring 13 ... reed valve 20 ... control valve 22 ... valve body 23 ... diaphragm P _c ... control pressure P _d ... discharge pressure P _s ... suction pressure V _a ... working space V _c ... control pressure chamber V _d ... Discharge pressure chamber V _s … suction pressure chamber

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhide Uchida 14 Iwatani, Shimowasumi-cho, Nishio-shi, Aichi Prefecture Inside the Japan Automobile Parts Research Institute Co., Ltd. (72) Hideaki Sasaya 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture (56) References JP-A-62-67288 (JP, A) JP-A-4-19383 (JP, A) JP-A-1-162094 (JP, U) (58) Fields surveyed (Int .Cl. ⁷ , DB name) F04C 18/02 311 F04C 29/10 311

Claims (4)

(57) [Claims] A fixed scroll member including an end plate and an involute blade fixed on the end plate; an end plate; and an involute blade fixed on the end plate. A movable scroll member forming a plurality of working spaces, and a discharge port formed substantially at the center of an end plate of the fixed scroll member and discharging fluid compressed toward the discharge pressure chamber as the volume of the working space decreases. A suction pressure chamber for supplying a fluid to the working space; a bypass hole formed in an end plate of the fixed scroll member and communicating the working space and the suction pressure chamber; and an end plate of the fixed scroll member. A cylinder formed in a straight line so as to intersect the bypass hole, and a plunger slidably incorporated in the cylinder to open and close the bypass hole. Holes, scroll compressor, characterized in that said a long hole along the shape of an involute vane of the movable scroll. 2. The scroll-type variable displacement compressor according to claim 1, wherein said bypass hole is formed such that a width of said elongated hole is smaller than a width of an involute blade of said movable scroll. 3. The compressor according to claim 2, wherein the bypass hole is formed on a plurality of straight lines, and the capacity of the compressor is varied stepwise by the plunger opening and closing the plurality of bypass holes sequentially. 2. The scroll-type variable displacement compressor according to 1. 4. The scroll-type variable capacitor according to claim 1, wherein the bypass hole is formed along the involute blade at a position near the involute blade in the end plate of the fixed scroll. Compressor.