CN1182194A - Variable capacity compressor - Google Patents

Abstract

A compressor has a cam plate that is mounted on a drive shaft for integral rotation therewith and tiltable between its maximum inclining position and its minimum. The piston is coupled to the cam plate. The piston reciprocates in a cylinder bore and compresses gas that is supplied to the cylinder bore from an external gas circuit and discharge the compressed gas to the external gas circuit that is connected to the interior of compressor by way of a gas passage. The low pressure side of the inner and outer gas loop is connecting to the gas passage. The compressor also comprises a separating body which cuts off the gas passage from the outer gas loop when the compressor stops running.

Description

Variable displacement compressor

The present invention relates to a kind of variable displacement compressor.The oil that particularly relates in the refrigerant gas that a kind of utilization is comprised in inner loop lubricates the variable displacement compressor of each structure.

In general, in the inside of variable displacement compressor, crank chamber is divided into discharge chamber and suction chamber by the cylinder block that constitutes a part of compressor case.Centre in aforementioned cylinder block is provided with through hole, is equiangularly formed several cylinder-bore around this through hole.Aforementioned through hole communicates with suction chamber and external refrigeration loop, from the external refrigeration loop through this through hole refrigerant gas is imported in the suction chamber.

In aforementioned crank chamber, be supported on to the tiltable action inclination angle of the cam disc on the driving shaft, change according to the pressure reduction between the pressure in the pressure in the crank chamber and each cylinder-bore.The mobile stroke of the piston in each cylinder-bore is according to the inclination angle variation of cam disc.When the inclination angle of cam disc increased, the discharge capacity of compressor rose, and when reduced at the inclination angle, the discharge capacity reduced.

Discharging the chamber links to each other with crank chamber by the supply passageway that forms on the cylinder block.Capacity control drive is arranged in the way of supply passageway, is used to adjust crank indoor pressure, and control is supplied with the refrigerant gas amount of crank chamber from discharging the chamber.

In above-mentioned compressor, the guiding valve shape that is arranged in the cylinder block through hole cuts off body, by moving with the inclination interlock of cam disc.So,, cut off the body restriction and suck being communicated with of path and suction chamber according to the minimizing at the inclination angle of cam disc.When cam disc is in minimum angle-of-incidence, cuts off body and will suck path and suction chamber partition.

Utilize the effect of control valve, when supplying with crank chamber in from discharging the chamber gas, the pressure in the crank chamber is risen, the inclination angle of cam disc increases once more.

Be in halted state at compressor, cut off the suction path fully if cut off body, the liquid refrigerant in the condensing externally refrigerating circuit can flow in the compressor because of the liquefaction of reasons such as extraneous gas temperature rising.The liquid refrigerant lubricating oil interior with being trapped in compressor that flows in the compressor in the halting process mixes.Afterwards, when compressor is restarted, liquid refrigerant because of foaming suddenly adverse current in the external refrigeration loop.As a result, cause the compressor inside can not sufficient lubrication.

Therefore, the purpose of this invention is to provide a kind of structure that can carry out good lubrication when after compressor stops, restarting to inside.

In order to finish above-mentioned purpose, the invention provides a kind of improved variable displacement compressor.This compressor has the cam disc on the driving shaft that can be contained in rotatably integratedly in the crank chamber.Cam disc is tilting action between inclination maximum position and minimum angle-of-incidence position.The piston that is connected with cam disc moves back and forth in cylinder-bore with the stroke corresponding to the cam disc inclination angle.Reciprocating motion by piston is compressed from the extraneous gas loop with gas supply cylinder hole.The gas that compresses in cylinder-bore is from discharging chamber row to outside gas return path.The inside of compressor is communicated with by gas return path with the extraneous gas loop.Compressor has, when compressor operation stops cutting off the partition body of gas passage and the mode application of force that is communicated with in extraneous gas loop.

Fig. 1 is the cutaway view of the variable displacement compressor of first embodiment of the invention.

Fig. 2 is the cutaway view of the swash plate of compressor shown in Figure 1 compressor when being in the minimum angle-of-incidence position.

Fig. 3 is the cutaway view of the compressor of the second embodiment of the present invention.

Fig. 4 is the cutaway view of the compressor of the third embodiment of the present invention.

With reference to Fig. 1, Fig. 2, first embodiment of the variable displacement compressor that the present invention specializes is described below.

Procapsid 12 engages with the front end of cylinder block 11.Back casing 13 is bonded together by the rear end of valve plate 14 with cylinder block 11, and crank chamber 15 is procapsid 12 inner formation of cylinder block 11 fronts one side.

Driving shaft 16 is supported on procapsid 12 and the cylinder block 11 rotationally.The front end of driving shaft 16 reaches the outside from crank chamber 15, belt pulley 17 is fixedly attached on this extension.Belt pulley 17 directly links to each other with external drive source (being meant vehicle motor E in the present embodiment) by belt 18.That is to say that the compressor of present embodiment is the no-clutch type variable displacement compressor that clutch is not set between a kind of driving shaft 16 and the external drive source.Belt pulley 17 is supported on the procapsid 12 by means of radial bearing 19.Procapsid 12 bears the load on the axially and radially both direction that acts on the belt pulley 17 by radial bearing 19.

Between the front end periphery of driving shaft 16 and procapsid 12, lip seal 20 is installed.Lip seal 20 prevents the pressure leakage in the crank chamber 15.

Substantially make discoid swash plate 22, be supported on the driving shaft 16 in the crank chamber 15, can slide along the axis of axle 16 and tilt with respect to this axis.The a pair of guide finger 23 that front end has SDeflector is fixedly connected on the swash plate 22.Rotary body 21 is fixed on the driving shaft 16 in the crank chamber 15, and can be with driving shaft 16 unitary rotation.Rotary body 21 has towards the side-prominent support arm 24 of swash plate 22 1.On support arm 24, form a pair of pilot hole 25.In pilot hole 25, embed guide finger 23 respectively slidably.By cooperating of support arm 24 and guide finger 23, swash plate 22 can be with driving shaft 16 unitary rotation.In addition, by cooperating of support arm 24 and guide finger 23, to swash plate 22 moving and oriented along the axis of axle 16.Along with swash plate 22 towards the moving of cylinder block 11 1 sides (rear), its inclination angle reduces.

First helical spring 85 is installed between rotary body 21 and swash plate 22.First helical spring 85 towards the rear (swash plate 22 inclination angles reduce direction) to swash plate 22 application of forces.In addition, form protuberance 21a, limit swash plate 22 with contacting of protuberance 218, swash plate 22 is in does not cross the position of being scheduled to inclination maximum and tilting by swash plate 22 in the back of rotary body 21.

Central part in cylinder block 11 is equipped with the installing hole 27 that extends along the axis direction of driving shaft 16.The tubular that the end sealing that can slide along the axis direction of driving shaft 16 is installed in installing hole 27 cuts off body 28.Cutting off body 28 is made up of large-diameter portion 28a and minor diameter 28b.Between the inner peripheral surface of the step of large-diameter portion 28a and minor diameter 28b and installing hole 27, second helical spring 86 is installed.86 pairs of second helical springs cut off body 28 towards the swash plate 22 1 side application of forces.The elastic force of first helical spring 85 is greater than the elastic force of second helical spring 86.

The rearward end of driving shaft 16 is inserted in the tube that cuts off body 28.Radial bearing 30 is fixed on the inner peripheral surface of large-diameter portion 28a by circlip 31.But radial bearing 30 relative drive shafts 16 slide.The rear end of driving shaft 16 is supported on the inner peripheral surface of installing hole 27 by radial bearing 30 and partition body 28.

Central part at back casing 13 and valve plate 14 forms suction path 32, sucks axis extension and the formation suction pressure district of path 32 along driving shaft 16.The inner that sucks path 32 is communicated with installing hole 27.In the inner around openings that sucks path 32, on valve plate 14, form locating surface 33.The rear end face that cuts off body 28 can contact with locating surface 33.Rear end face by cutting off body 28 33 contact with the location, has limited partition body 28 motion of (towards the direction of leaving swash plate 22) towards the rear, will suck path 32 and installing hole 27 partitions simultaneously.

On the driving shaft 16 between swash plate 22 and the partition body 28, supporting thrust bearing 34 movably along axis direction.Thrust bearing 34 is clipped in swash plate 22 all the time and cuts off between the body 28 by the application of force of second helical spring 86.Thrust bearing 34 stops the rotation of swash plate 22 to pass to and cuts off body 28.

Swash plate 22 is along with the minimizing at its inclination angle is rearward moved.When swash plate 22 is rearward mobile, will cuts off body 28 by last thrust bearing 34 and press to the rear.Thus, cutting off body 28 overcomes the elastic force of second helical spring 86 and shifts to locating surface 33 1 sides.Shown in the dotted line and solid line of Fig. 1 and Fig. 2, the inclination angle of swash plate 22 reaches hour, cuts off body 28 rear end faces and contacts with locating surface 33.Cut off body 28 and be arranged on the position that to close the connection that sucks path 32 and installing hole 27.

Several cylinder-bore 11a passes cylinder block 11 and forms, and parallels with the axis of driving shaft 16.Each cylinder-bore 11a is configured in around the driving shaft 16 equally spacedly.Deposit single head pison 35 is installed in each cylinder-bore 11a.The hemisphere portion of a pair of piston shoes 36 is embedded on each single head pison 35 slidably.Swash plate 22 by the planar portions clamping slidably of two piston shoes 36.The revolution of driving shaft 16 passes to swash plate 22 by rotary body 21.Rotatablely moving of swash plate 22 converts the reciprocating motion of piston 35 in cylinder-bore 11a to by piston shoes 36.

Central portion forms suction chamber 37 in back casing 13.Suction chamber 37 is communicated with installing hole 27 by connected entrance 45.In back casing 13, around suction chamber 37, form and discharge chamber 38.On valve plate 14, form suction inlet 39 and the outlet 40 corresponding respectively with each cylinder-bore 11a.On valve plate 14, also form and this each suction inlet 39 and corresponding respectively inlet valve 41 and the dump valve 42 of each outlet 40.

Each piston 35 in cylinder-bore 11a from top dead-centre when bottom dead centre moves, the refrigerant gas in the suction chamber 37 flow in the cylinder-bore 11a from suction inlet 39 pushing inlet valves 41.Each piston 35 in cylinder-bore 11a from top dead-centre when bottom dead centre moves, after the refrigerant pressure in each cylinder-bore 11a contracts, discharge to discharging chamber 38 from outlet 40 pushing dump valves 42.The baffle plate 43 of dump valve 42 and valve plate 14 contact the aperture that has limited this valve.

Between rotary body 21 and procapsid 12, thrust bearing 44 is installed.Thrust bearing 44 is accepted to act on compression counter-force on the rotary body 21 by piston 35 and swash plate 22 etc.

In driving shaft 16, form pressure release path 46.Pressure release path 46 has near the inlet 46a the lip seal 20 in crank chamber of being opened on 15 and is opened on the outlet 46b that cuts off body 28 inside.Pressure release through hole 47 forms on the side face of the rearward end of cutting off body 28, and the inside that cuts off body 28 is communicated with installing hole 27.

For discharge chamber 38 is connected with crank chamber 15, on back casing 13, valve plate 14 and cylinder block 11, form supply passageway 48.Capacity control drive 49 is arranged in the way of supply passageway 48, and is installed on the back casing 13.In addition, on the back casing 13 that sucks between path 32 and the control valve 49, form and import path 50, be used for suction pressure Ps is imported in this control valve 49.

On cylinder block 11, form outlet 51, be connected with discharge chamber 38.External refrigeration loop 52 is connected outlet 51 with suction path 32.Condenser 53, expansion valve 54 and evaporimeter 55 externally are installed in the refrigerating circuit 52.Near evaporimeter 55, be provided with temperature sensor 56.Temperature sensor 56 is used to detect the temperature of evaporimeter 55, will be defeated by computer 57 according to the resulting signal of this detected temperatures.In addition, computer 57 and the room temperature setting apparatus 58 that is used to set the vehicle indoor temperature, the temperature sensor 59 that is used to detect the vehicle indoor temperature, the driving switch 60 that is used to drive aircondition and engine speed sensor 61 etc. are connected.

The rotating speed of the detected temperatures that computer 57 obtains according to the detected temperatures that for example obtains by room temperature setting apparatus 58 predefined room temperatures, from sensor 56, from sensor 59, the engine E that obtains from sensor 61 and the various conditions such as ON/OFF state of driving switch 60 are sent instruction with the current value that imposes on control valve 49 to driving loop 62.Drive loop 62 and will send the coil 63 that the electric current of command value flows to the solenoid 65 of control valve 49 described later, decision imposes on the condition of the current value of control valve 49, comprises the rotating speed etc. of vehicle outdoor temperature and engine E and the condition beyond the above-mentioned condition.

Above-mentioned control valve 49 is connected valve chest 64 and the valve chamber 66 between the solenoid 65 that engages one another on the discharge chamber 38 by supply passageway 48.The valve body 67 that is provided with in the valve chamber 66 contacts with valve opening 68 parameatal valve seats.Between the inner face of valve body 67 and valve chamber 66, helical spring 69 is installed.

Pressure-sensitive chamber 71 is formed at the top in valve chest 64, and this pressure-sensitive chamber 71 is communicated with suction path 32 by importing path 50.Be configured in the bellows 73 of 71 inside, pressure-sensitive chamber, detect by importing path 50 from sucking the suction pressure Ps that path 32 imports in the pressure-sensitive chamber 71.First bar 75 that bellows 73 is linked to each other with valve body 67 is connected on the valve body 67.Valve opening 68 is connected on the crank chamber 15 by supply passageway 48.

In solenoid 65, be formed centrally installing hole 77, be fixed with secured core 78 chimericly.The reciprocating plunger that is fabricated from iron 80 is installed in installation room 79, helical spring 81 is installed between the inner bottom surface of plunger 80 and installing hole 77, the elastic force of the elasticity rate said spiral spring 69 of this helical spring 81 is little.Spring 69 is downwards to valve body 67 application of forces.The power that spring 81 applies plunger 80 upward.The front end of second bar 83 contacts with plunger 80 all the time.In other words, valve body 67 moves with plunger 80 one by second bar 83.

Around secured core 78 and plunger 80, be provided with cylindric coil 63.According to the instruction of computer 57, the rated current value in self-driven loop 62 is supplied with this coil 63 in the future.

When compressor is in the ON state at driving switch 60, and by temperature sensor 59 detected vehicle indoor temperatures be the above occasion of setting value, computer 57 is by 62 pairs of solenoid 65 excitations in driving loop.Thus, electric current supply coil 63, between secured core 78 and plunger 80, produce attraction corresponding to current value.Thereby, on valve body 67, produce the power that overcomes spring 69 towards close valve orifice 68 directions.On the other hand, bellows 73 bases are from sucking path 32 displacement by the variation of the suction pressure Ps of importing path importing pressure-sensitive chambers 71 50.The displacement of this bellows 73 passes to valve body 67.Bellows 73 shrinks, and suction pressure Ps suitably increases, and valve body 67 moves towards the locking direction.

Like this, aperture according to the valve opening 68 of valve body 67, determining according to a plurality of equilibrium of forces that act on the valve body 67, specifically, is that the balance between the elastic force that applies of the power that applies according to the power that is applied by second bar 83 by solenoid 65, by bellows 73 and spring 69 is determined.

In the occasion that refrigerating plant load increases, for example, in the occasion of the temperature that is detected by temperature sensor 59 with the difference increase of the design temperature of room temperature setting apparatus 58, suction pressure Ps also increases.Computer 57 makes the electric current of the coil 63 of supplying with control valve 49 become big, and the difference of detected temperatures and design temperature increases in right amount.Thereby, strengthened the attraction between secured core 78 and the plunger 80, increased the power of valve body 67 being pushed to valve opening 68 closing directions.Therefore, will make valve body 67 move needed suction pressure value Ps and set low value for to close valve orifice 68 directions.So valve body 67 moves, the aperture of valve opening 68 is adjusted according to lower suction pressure Ps.In other words, control valve 49 moves along with the increase of supplying with current value, keeps lower suction pressure Ps.

In case when valve body 67 reduces the aperture of valve opening 68, reduce from discharging the refrigerant gas amount of supplying with in crank chamber 15 through supply passageway 48 chamber 38.On the other hand, the refrigerant gas in the crank chamber 15 flows to suction chamber 37 through pressure release path 46 and relief hole 47.Thus, the pressure P c in the crank chamber 15 reduces.Cause that suction pressure Ps increases under the state that refrigerating plant load increases, thus, the pressure in the cylinder-bore 11a also increases.And then pressure P c in the crank chamber 15 and the pressure reduction between the pressure in the cylinder-bore 11a reduce, and the inclination angle of swash plate 22 increases, and compressor turns round under big discharge capacity.

When the complete close valve orifice 68 of the valve body 67 of control valve 49, supply passageway 48 is closed, and does not supply with higher pressure refrigerant gas from discharging chamber 38 to crank chamber 15.So the low-pressure Ps in pressure P c in the crank chamber 15 and the suction chamber 37 is roughly the same.Therefore, as shown in Figures 3 and 4, the inclination angle of swash plate 22 becomes maximum, and compressor turns round under maximum discharge capacity.Swash plate 22 by with the contacting of the protuberance 21a of rotary body 21, make swash plate 22 be in the position that is no more than predetermined inclination maximum and tilts.

On the contrary, the occasion that diminishes at the load of refrigerating plant, the occasion that diminishes in the difference of the temperature that detects by temperature sensor 59 and the temperature of room temperature setting apparatus 58 settings for example, suction pressure Ps also diminishes.Computer 57 is issued instruction and is driven loop 62, and the difference of detected temperature and design temperature is diminished, and the current value that is fed in the coil 63 of control valve 49 also diminishes.Thus, the attraction between secured core 78 and the plunger 80 dies down, and has reduced the power size that valve body 67 is promoted towards close valve orifice 68 directions.Like this, the direction that makes valve body 67 to close valve orifice 68 is moved needed suction pressure Ps and set high value for.Therefore, according to 67 actions of higher suction pressure Ps valve body, adjust the aperture of valve opening 68.In other words, control valve 49 moves along with the minimizing of supplying with current value, keeps higher suction pressure Ps.

If valve body 67 makes the aperture of valve opening 68 become big, just increase from discharging the refrigerant gas amount of supplying with to crank chamber 15 chamber 38, the pressure P c in the crank chamber 15 rises.In addition, under the state that refrigeration load diminishes, because suction pressure Ps reduces, the pressure in the cylinder-bore 11a also reduces.Like this, pressure P c and the pressure reduction between the pressure in the cylinder-bore 11a in the crank chamber 15 become big, and the inclination angle of swash plate 22 diminishes, and compressor turns round under float goes out capacity.

When the state that refrigerating plant gradually pursues near the no operatton load, the temperature of the evaporimeter 55 in the external refrigeration loop 52 slowly reduces, near the initial temperature that produces frost.When the temperature that detects by temperature sensor 56 when the initial temperature that produces frost is following, 57 pairs in computer drives loop 62 and sends the instruction that makes solenoid 65 demagnetizations.So, stop electric current supply to coil 63, do not produce attraction between secured core 78 and the plunger 80.Like this, as shown in Figure 5, valve body 67 overcomes by the elastic force of spring 69 by the spring 81 of plunger 80 and 83 effects of second bar, and moves to the direction that valve opening 68 is opened.As a result, valve body 67 makes the aperture maximum of valve opening 68.Thus, further increase from discharge the refrigerant gas of supplying with chamber 38 in crank chamber 15, the pressure P c in the crank chamber 15 continues to raise.Thereupon, the inclination angle of swash plate 22 becomes minimum, and compressor turns round under minimum discharge capacity.

When driving switch 60 was in OFF (closing) position, 57 pairs in computer drove loop 62 and sends the instruction that makes solenoid 65 demagnetizations.Like this, the inclination angle of swash plate 22 becomes minimum.

In sum, the valve body 67 of control valve 49 not only becomes big degree and lower suction pressure Ps according to the current value of supplying with coil 63 and moves, adjust the aperture of valve opening 68, in addition, also degree and the high suction pressure Ps that diminishes according to supply coil 63 current values moves, and adjusts the aperture of valve opening 68.Compressor can be kept as target suction pressure Ps, the inclination angle of control swash plate 22, and then adjust the discharge capacity.Therefore, control valve 49 had both been undertaken the task according to the setting value of the current value change suction pressure Ps that supplies with, also make compressor with the irrelevant situation of suction pressure Ps under turn round with minimum capacity.Compressor with this control valve 49 plays the effect of the refrigerating capacity that changes aircondition.

With the partition body 28 of the inclination of swash plate 22 interlock,, slowly reduce from sucking the cross-sectional area of path 32 to the gas flow path between the suction chamber 37 along with the minimizing at swash plate 22 inclination angles.This makes from sucking the refrigerant gas amount that path 32 flows to suction chamber 37 and reduces gradually.Thus, also reduce gradually to the inner refrigerant gas amount that sucks of cylinder-bore 11a from suction chamber 37, the discharge capacity reduces gradually.Therefore, discharge pressure Pd reduces gradually, and needed moment of torsion tails off gradually during the driving of compressor.As a result, can avoid that big change takes place moment of torsion at short notice when changing to minimum discharge capacity from maximum discharge capacity, and relax the impact that causes along with the moment of torsion change.

When the inclination angle of swash plate 22 becomes hour, cut off body 28 and contact with locating surface 33.Bump when connecing when cutting off body 28 and locating surface 33, swash plate 22 is limited in the state of minimum angle-of-incidence, simultaneously, cut off and suck being communicated with of path 32 and suction chamber 37.Therefore, refrigerant gas can be from the external refrigeration loop 52 flow into suction chambers 37, has stoped circulating through the circulating refrigerant gas of external refrigeration loop 52 and compressor.

Because the minimum angle-of-incidence of swash plate 22 is bigger slightly than 0 °.And the angle of swash plate 22 on the plane that is arranged at driving shaft 16 axis normal the time is 0 °.Therefore, even the inclination angle of swash plate 22 becomes minimum, refrigerant gas also can turn round compressor from cylinder-bore 11a row to discharging chamber 38 under minimum discharge capacity.To the refrigerant gas of discharging chamber 38, flow into crank chamber 15 from cylinder-bore 11a row by supply passageway 48.Refrigerant gas in the crank chamber 15 is drawn in the cylinder-bore 11a by pressure release path 46, relief hole 47 and suction chamber 37 again.That is to say, be under the state of minimum angle-of-incidence at the inclination angle of swash plate 22, and refrigerant gas circulates in the peripheral passage of compressor inside through discharging chamber 38, supply passageway 48, crank chamber 15, pressure release path 46, relief hole 47, suction chamber 37 and cylinder-bore 11a.Along with this circulation, utilize the each several part in the oil lubrication compressor that is included in the refrigerant gas.

The state and the swash plate 22 that are in 0N at driving switch 60 keep under the state of minimum angle-of-incidence, when the refrigerating plant load being increased when rising along with the vehicle indoor temperature, be higher than design temperature by temperature sensor 59 detected temperature by temperature setting device 58, computer 57 sends the instruction that makes solenoid 65 excitations according to the rising of this detected temperatures to driving loop 62.When solenoid 65 excitations, close supply passageway 48, the refrigerant gas of discharging in the chamber 38 is supplied with in the crank chamber 15.Refrigerant gas in the crank chamber 15 flows to suction chamber 37 by pressure release path 46.Therefore, the pressure P c in the crank chamber 15 reduces at leisure, makes the inclination angle of swash plate 22 move to inclination maximum from minimum angle-of-incidence.

Along with the increase at swash plate 22 inclination angles, cut off the power that body 28 applies by second spring 86 and leave locating surface 33 gradually.Along with the carrying out of This move, the refrigerant gas amount that flows to suction chamber 37 from suction path 32 slowly increases.Thus, increase gradually to the inner refrigerant gas amount that sucks of cylinder-bore 11a from suction chamber 37, the discharge capacity increases gradually.Discharge pressure Pd is increased gradually, and needed moment of torsion becomes big gradually during driven compressor.As a result, row's capacity moment of torsion when minimum changes to maximum can not produce big variation at short notice, can relax the impact that causes with change in torque.

If engine E quits work, compressor just shuts down, and promptly swash plate 22 stops operating, and stops to the energising of the coil 63 of capacity control drive 49.Thus, solenoid 65 demagnetizations, supply passageway 48 is opened, and the inclination angle of swash plate 22 becomes minimum.If the state that shuts down of compressor continues, the pressure in the compressor is with regard to homogenising, and this makes swash plate 22 keep little inclination angle under the effect of first spring, 85 elastic force.Make and cut off contacting of body 28 and locating surface 33, keep the state of suction path 32 closures.Like this, in the compressor stopped process, can cut off being communicated with of external refrigeration loop 52 and compressor inside fully.Afterwards, even through the long-time state of going up that stops that still continues to keep compressor, also can stop externally refrigerating circuit 52 condensing liquid refrigerants to flow into compressor inside.

From as can be seen above-mentioned, when starting the compressor starts running, a spot of liquid refrigerant is arranged owing in compressor, only accumulate along with engine E, therefore can suppress the foaming of liquid refrigerant.Thus, can prevent to accumulate in the interior lubricating oil of compressor and sneak in the liquid refrigerant, eliminate this lubricating oil and in compressor start, flowed in the external refrigeration loop 52, overcome the lubricated obstacle that causes compressor inside.

Fig. 3 shows the second embodiment of the present invention.In this embodiment, the arm 24 of supporter 21 is made the U word shape that the end of pilot hole 25 is sealed.Between this closure wall 92 and guide finger 23, set up first spring 91.First spring 91 towards the direction that swash plate 22 inclination angles are diminished to swash plate 22 application of forces.The elastic force of first spring 91 is greater than the elastic force that is used to open second spring 86 that cuts off body 28.

When compressor stopped, all room pressures of compressor are homogenising all, and at this moment, swash plate 22 is under the minimum angle-of-incidence state, and partition body 28 will suck path 32 and close.In this process, can stop liquid refrigerant to enter in the compressor from external refrigeration loop 52.Like this, when having prevented that compressor from restarting, because of the foaming of the liquid refrigerant of compressor inside causes lubricating oil flowing towards outside refrigerating circuit 52.

In addition, when the pressure in the crank chamber 15 reduced, high temperature and high pressure gas stream imported in the crank chamber 15 through path 48 from discharging chamber 38.Each position in the crank chamber 15 is exposed in the high temperature gas flow.Aforementioned first spring 91 is arranged in the U word shape arm 24, is not directly exposed in the gas stream.Thereby first spring 91 is subjected to through the influence of the high temperature gas flow that flows in the crank chamber smaller, can prevent that it is aging prematurely.

Hereinafter narrate the third embodiment of the present invention according to Fig. 4.In this embodiment, the parts identical with the foregoing description 1 represent with identical label, therefore only concentrate the part different with embodiment 1 described.

The second suction path 101 that forms on cylinder block 11 is communicated with installation room 27 with crank chamber 15.Supply with the refrigerant gas of installation room 27 through in the second suction path, the 101 importing crank chamber 15 from sucking path 32.

Importing path 102 links to each other crank chamber 15 with suction chamber 37.Refrigerant gas imports suction chamber 37 through importing path 102 from crank chamber 15.Import path 102 and comprise first path 146, intercommunicating pore 104, alternate path 103, valve chamber 105 and through hole 105a.First path 146 forms in driving shaft 16, and its axis along driving shaft 16 is extended.First path 146 has the inlet 146a near the crank chamber 15 that is opened on the lip seal 20 and is opened on the outlet 146b that cuts off in the body 28.The intercommunicating pore 104 that forms on partition body 28 side faces will cut off the inside of body 28 and formed alternate path 103 connections on cylinder block 11 and valve plate 14.The valve chamber 105 that forms on the back casing 13 links to each other with alternate path 103.Through hole 105a is communicated with valve chamber 105 with suction 37.

Tapered hole 106 is made in the outlet of alternate path 103.The valve body 107 that constitutes guiding valve is configured in the valve chamber 105 movably.Valve body 107 has the taper restriction 108 that is provided with in the face of tapered hole 106.Spring 109 is arranged between the surface, inside of valve body 107 and valve chamber 105.This spring 109 is towards the direction application of force that makes valve body 107 away from tapered hole 106.

Controlled pressure chamber 111 is to form by valve chamber 105 inside are divided from the rear side of valve body 107.Pressure feed path 110 forms on back casing 13, will discharge chamber 38 and be communicated with controlled pressure chamber 111.Capacity control drive 49 is installed in the back casing 13, and places the way of pressure feed path 110.Pressure release path 112 forms on back casing 13, valve plate 14 and cylinder block 11, and controlled pressure chamber 111 is communicated with crank chamber 15.

During above-mentioned compressor operation, refrigerant gas from external refrigeration loop 52 through suck path 34, installing hole 27 and second sucks path 101 and supplies with in the crank chamber 15.Refrigerant gas in the crank chamber 15 imports in the suction chamber 37 through the importing path 102 that includes alternate path 146, intercommunicating pore 104, alternate path 103, valve chamber 105 and through hole 105a.Therefore, in this embodiment, a part of path that crank chamber 15 constitutes between external refrigeration loop 52 and the suction chamber 37.

In the occasion that the refrigerating plant load increases, the current value of supplying with the coil 63 of control valve 49 becomes big.The attraction that this has strengthened between secured core 78 and the plunger 80 has increased the power of valve body 67 being pushed to valve opening 68 closing directions in fact.In case when valve body 67 reduces the aperture of valve opening 68, reduce through the refrigerant gas amount that supply passageway 110 flows to controlled pressure chamber 111 from discharging chamber 38.On the other hand, the refrigerant gas in the controlled pressure chamber 111 flows to crank chamber 15 through pressure release path 112.Thus, the pressure in the controlled pressure chamber 111 reduces, and valve body 107 (away from the direction of taper hole 106) towards the rear moves.Like this, the amount of restriction of the taper hole 106 that is caused by the tapering 108 of valve body 107 diminishes.When amount of restriction diminishes, when the aperture that is to say taper hole 106 becomes big, increase through the refrigerant gas amount that imports paths 102 and flow into suction chambers 37 from crank chamber 15, the pressure in the suction chamber 37 are raise.And then pressure P c in the crank chamber 15 and the pressure reduction between the pressure in the cylinder-bore 11a reduce, and the inclination angle of swash plate 22 increases, and compressor turns round under big discharge capacity.

When the complete close valve orifice 68 of the valve body 67 of control valve 49, supply passageway 110 is closed, not from discharging chamber 38 to controlled pressure chamber 111 the supply system refrigerant gas.So the pressure of controlled pressure chamber 111 further reduces, make the aperture of taper hole 106 become maximum by valve body 107.As a result, pressure in the suction chamber 37 and the pressure P c in the crank chamber 15 are roughly the same.The inclination angle of swash plate 22 becomes maximum, and compressor turns round under maximum discharge capacity.Closed by control valve 49 under the state of supply passageway 110, the higher pressure refrigerant gas of discharging in the chamber 38 is supplied with in the crank chamber 15 without supply passageway 110 and pressure release path 112, but is fed in the external refrigeration loop 52.

On the contrary, in the occasion that the load of refrigerating plant diminishes, the current value that is fed in the coil 63 of control valve 49 also diminishes.Thus, the attraction between secured core 78 and the plunger 80 diminishes, and has reduced the power size that valve body 67 is promoted towards close valve orifice 68 directions in fact.If valve body 67 makes the aperture of valve opening 68 become big, just increase through the refrigerant gas amount that supply passageway 110 flows to controlled pressure chamber 111 from discharging chamber 38.Pressure in the controlled pressure chamber 111 raises, and (near the direction of taper hole 106) moves valve body 107 towards the place ahead.Like this, increased the amount of restriction of 108 pairs of taper holes 106 of restriction of valve body 107.When the throttling quantitative change was big, when the aperture that is to say taper hole 106 diminished, to flow into the refrigerant gas quantitative change of suction chambers 37 few through importing paths 102 from crank chamber 15, and the pressure in the suction chamber 37 reduce.Thereby pressure P c and the pressure reduction between the pressure in the cylinder-bore 11a in the crank chamber 15 become big, and the inclination angle of swash plate 22 diminishes, and compressor turns round under float goes out capacity.

Under the state of refrigerating plant no operatton load, stop electric current supply to the coil 63 of control valve 49, make between secured core 78 and the plunger 80 and do not produce attraction.This is to become maximum position because valve body 67 is arranged on the aperture that makes valve opening 68, makes the aperture of supply passageway 110 become maximum.Thereby, further increasing from discharging the refrigerant gas amount of supplying with to controlled pressure chamber 111 chamber 38, the pressure in the controlled pressure chamber 111 further raises.So valve body 107 continues forwards to move, and makes the amount of restriction of taper hole 106 become maximum by valve body 107.When the throttling quantitative change was big, the refrigerant gas quantitative change that flows into suction chamber 37 from crank chamber 15 was few, and the pressure in the suction chamber 37 further reduces.The inclination angle of swash plate 22 becomes minimum, and compressor turns round under minimum discharge capacity.

When the inclination angle of swash plate 22 becomes hour, cut off body 28 and close and suck path 32.Like this, do not allow cold-producing medium 52 flow into suction chambers 37 from the external refrigeration loop.In this state, refrigerant gas is through discharging chamber 38, supply passageway 110, pressure controling chamber 111, pressure release path 112, crank chamber 15, importing the peripheral passage circulation in path 102, suction chamber 37 and these compressors of cylinder-bore 11a.

In this embodiment, in the compressor stopped process, also can be done so that the room pressure homogenising that compressor is whole.Therefore, swash plate 22 inclination angles are in minimum state, cut off body 28 and will suck path 32 sealings.In the meantime, can stop liquid refrigerant to be gone the same way and 52 enter in the compressor, have only a spot of liquid refrigerant to be trapped in the compressor from external refrigeration.As a result, because of making lubricating oil flow to external refrigeration, the foaming of the liquid refrigerant in the compressor goes the same way 52 in the time of can avoiding compressor to restart.

Claims (5)

1, a kind of compressor, be equipped with on the driving shaft (16) in crank chamber (15) can one the rotation and the cam disc (22) that can between inclination maximum and minimum angle-of-incidence position, tilt, piston (35) basis that is connected with cam disc (22) moves back and forth in cylinder-bore (11a) corresponding to the stroke at the inclination angle of cam disc (22), thus, after will compressing from the gas in the supply cylinder hole, extraneous gas loop (52) (11a), be discharged to extraneous gas loop (52) through discharging chamber (38), the inside of aforementioned compressor is connected by gas passage (32) with the low-pressure side of extraneous gas loop (52), it is characterized in that, aforementioned compressor also comprises partition body (28), and this partition body (28) can cut off gas passage (32) and extraneous gas loop (52) when the running of aforementioned compressor stops.

2, compressor according to claim 1 is characterized in that, aforementioned partition body (28) links with the inclination of cam disc (22), and when cam disc (22) was in the minimum angle-of-incidence position, partition gas passage (32) was communicated with extraneous gas loop (52).

3, compressor according to claim 1 and 2 is characterized in that, aforementioned cam disc (22) is by first spring (85; 91) and second spring (86) respectively in the minimum angle-of-incidence position and the inclination maximum position application of force, aforementioned first spring (85; 91) elastic force is greater than the elastic force of second spring (86).

4, compressor according to claim 3, it is characterized in that, when the pressure in the aforementioned crank chamber (15) reduces, from discharging chamber (38) gas stream is supplied with in the crank chamber (15), aforementioned first spring (91) is arranged on the position outside the zone of mainly passing through of discharging chamber (38) gas supplied stream in the crank chamber (15).

5, compressor according to claim 4, it is characterized in that, but the rotary body (21) that is arranged at aforementioned driving shaft (16) in one is rotatably gone up the gathering sill (25) that forms end sealing, in aforementioned cam disc (22) go up to form through gathering sill (25) guiding, make cam disc (22) with respect to rotary body (21) but the part (23) that is connected with this cam disc (22) that tiltable and one are rotated, aforementioned first spring (91) is set in the gathering sill (25), towards making cam disc (22) become the direction application of force of minimal tilt position.

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