CN2709679Y - Vortex compressor - Google Patents

Abstract

The utility model relates to a scroll compressor, particularly a scroll compressor taking measures for preventing too high exhaust temperature. The utility model suppresses the excessive rise of the exhaust temperature, and causes the scroll compressor to continuously run. The utility model is provided with a valve mechanism 51 in one end plate 21a of a fixed swirl disk 21. The valve mechanism 51 works along with the pressure difference between a compression chamber 37 and a low pressure chamber 36 in the compression process in a closed state, and communicates a high pressure chamber 45 with the low pressure chamber 36 only when the pressure difference is lower than the prescribed value. In this way, when the refrigerant pressure of the low pressure chamber 36 reduces under the condition of pump-out operation, etc., high pressure refrigerant gas leaks to the low pressure chamber 36, and the compression ratio is restrained from becoming too large. The scroll compressor of the utility model can be used for compressing refrigerants, etc.

Description

Scroll compressor

Technical field

The utility model relates to scroll compressor, particularly, is related to and prevents the scroll compressor of taking measures owing to excessive discharge temperature.

Background technique

In the past, using scroll compressor as the compressor that comes compression refrigerant gas with freeze cycle always.This scroll compressor has fixed scroll and rotation scroll in casing.These two kinds of scroll have end plate respectively, and protrude the Vorticose vortex circle that is arranged on this end plate.Fixed scroll is fixed on the casing, and the rotation scroll is connected on the eccentric part of live axle, can revolve round the sun.The vortex circle of this rotation scroll does not carry out rotation under the state that the vortex circle with fixed scroll meshes, only revolve round the sun.Like this, formed pressing chamber just can dwindle continuously between two scroll, with the gas in the compression pressing chamber.

, in above-mentioned scroll compressor, for example,, recognized that the temperature of the fluid of discharging from pressing chamber can excessively raise as disclosing in the patent documentation 1 (No. 3084105 patent gazette).That is, for example, under the expansion valve closing state, make under the situation that compressor finds time to turn round etc., the temperature of the refrigerant of discharge will raise unusually.This be because, under the also still very high situation of the pressure of the exhaust side of compressor, just the pressure of suction side is lowered, compare the cause that increases unusually when making compression ratio with usual running.

And when the refrigerant temperature of discharging raise unusually, the vortex circle of scroll will expand, and it is excessive that the surface pressure between its top end and the end plate just becomes, and vortex circle and end plate just may wear and tear or damage.In addition, the frictional heat that produces owing to the slip between the scroll has increased, and is superimposed with the rising of delivery temperature, and oily temperature just rises, and impels the lubricant oil of refrigerating machine to become bad, may become the reason of insufficient lubrication.

In order to solve this problem that produces owing to unusual intensification, in the scroll compressor that in above-mentioned patent documentation 1, is disclosed, the hyperthermia induced cryogen of discharging by means of making leaks in the low-pressure section that is provided with drive motor, this drive motor is heated up, thereby stop compressor operation.

Specifically, in this compressor,, in this low-pressure section, be provided with drive motor in the inner low-pressure section that forms the low-pressure refrigerant that is full of suction of casing.On the other hand, the bifurcated passage that is communicated with low-pressure section is connected on the exhaust passage of the flow of refrigerant of discharging from pressing chamber.On the attachment portion of the bifurcated passage on this exhaust passage, be provided with the valve of dual metal type.When the excessive temperature of the refrigerant of discharging rose, this dual metal type valve was just opened.Like this, when the excessive temperature of the refrigerant of discharging rose, the dual metal type valve was just worked, and the hyperthermia induced cryogen guiding low-pressure section with discharging rises the temperature of drive motor.Then, the temperature that the temperature transducer that the protection motor is used detects drive motor has risen, and compressor is shut down, thereby avoided compressor to remain in operation under the very high state of delivery temperature.

, the compressor in the past that discloses in above-mentioned communique is because its structure is when delivery temperature excessively rises, drive motor is stopped operating, so, for example, when finding time to turn round, drive motor has just stopped at once, has produced the problem that it is remained in operation of being difficult to.In addition, because compressor starts repeatedly and stops, may damaging the reliability of compressor.

Summary of the invention

Therefore, the utility model because above this some and put forward, its objective is provides a kind of like this scroll compressor, the improvement of this scroll compressor by scroll is scheduled to, suppress the excessive rising of delivery temperature, made scroll compressor to remain in operation.

For achieving the above object, in the utility model, be conceived to pressure according to low pressure chamber 36, to the pressing chamber 37 that under closed state, carries out compression process with and the low pressure chamber 36 that is communicated with of sucking pipe 18 between pressure difference increase and decrease, be provided with the valve mechanism 51 of working according to the above-mentioned pressing chamber 37 and the pressure difference of low pressure chamber 36, only when this pressure difference is lower than specified value, hyperbaric chamber 45 connections that make above-mentioned low pressure chamber 36 and is communicated with outlet pipe 19.

Specifically, the prerequisite of first model utility is a kind of scroll compressor, it has the casing 11 that sucking pipe 18 and outlet pipe 19 have been installed, and has an a pair of scroll 21,22 that is vertically set on the last Vorticose vortex circle 21b of end plate 21a, 22a, 22b, and be arranged on the compressing mechanism 15 in the said machine casing 11, fluid is from the pressing chamber 37 of the above-mentioned low pressure chamber that is communicated with sucking pipe 18 36 suction above-mentioned compressor structures 15, and fluid is arranged to the hyperbaric chamber 45 that is communicated with above-mentioned outlet pipe 19 from above-mentioned pressing chamber 37.And, also have according to above-mentioned pressing chamber 37 in the compression process of under closed state, carrying out and the pressure difference between the above-mentioned low pressure chamber 36 and carry out work, only be lower than when equaling specified value the valve mechanism 51 that above-mentioned hyperbaric chamber 45 is communicated with low pressure chamber 36 in above-mentioned pressure difference.

In addition, second model utility is in first model utility, and valve mechanism 51 has following various parts: the cylinder chamber 53 that forms on end plate 21a, the 22a of a scroll in scroll 21,22 at least; Insert in the above-mentioned cylinder chamber 53 and can freely advance and retreat, and the valve body 54 that can move according to the pressure difference of pressing chamber in the compression process of under closed state, carrying out 37 and low pressure chamber 36; Mouthful towards above-mentioned cylinder chamber 53, first communication passage 56 that is communicated with hyperbaric chamber 45; Mouthful towards above-mentioned cylinder chamber 53, second communication passage 57 that is communicated with low pressure chamber 36; Above-mentioned valve body 54 is applied power, make it can above-mentioned first communication passage 56 be communicated with second communication passage 57 and the position that cuts off between reciprocating spring members 55.

That is, in first model utility, the fluid outside casing 11 sucks low pressure chamber 36 by sucking pipe 18.This fluid sucks in the pressing chamber 37 of compressing mechanism 15 from low pressure chamber 36, compresses.Then, the fluid through overcompression in pressing chamber 37 enters hyperbaric chamber 45, derives casing 11 outsides by outlet pipe 19.In this model utility, valve mechanism 51 is to carry out work according to the pressing chamber 37 that carries out compression process under closed state and the pressure difference of low pressure chamber 36.When this pressure difference is lower than specified value, by valve mechanism 51 hyperbaric chamber 45 is communicated with low pressure chamber 36, the high-pressure liquid in the hyperbaric chamber 45 just flows into low pressure chamber 36.On the contrary, under above-mentioned pressure difference surpasses the state of specified value, by being communicated with between valve mechanism cutoff high chambers 45 51 and the low pressure chamber 36.

At this moment, for scroll compressor 10, under closed state, carry out in the pressing chamber 37 of compression process and with low pressure chamber 36 that sucking pipe 18 is communicated with in, both pressure ratios are certain.Therefore, both pressure differences are that promptly the pressure of low pressure chamber 36 increases and decreases according to the hydrodynamic pressure that sucks the pressing chamber 37 of compressing mechanism 15 from low pressure chamber 36.That is, for example, in the running of finding time, when the pressure of low pressure chamber 36 reduces, carry out the pressing chamber 37 of compression process and the pressure difference of low pressure chamber 36 and also diminish.

In above-mentioned first model utility, when owing to reasons such as the runnings of finding time, the pressure of low pressure chamber 36 reduces, and when the pressing chamber 37 in the compression process diminished with the pressure difference of low pressure chamber 36, valve mechanism 51 was just worked, and hyperbaric chamber 45 is communicated with low pressure chamber 36.In this state, the high-pressure liquid in hyperbaric chamber 45 flows into low pressure chamber 36, and the pressure of low pressure chamber 36 is risen, so the pressure of the fluid that compressing mechanism 15 sucks from low pressure chamber 36 also rises.Therefore, even when finding time to turn round, the pressure of the fluid that compressing mechanism 15 is sucked and the pressure in hyperbaric chamber 45 poor, just can not expand to a certain degree more than, the compression ratio of compressing mechanism 15 can not increase to heavens.

In addition, in second model utility, the valve body 54 of valve mechanism 51 is arranged in the cylinder chamber 53 that forms on end plate 21a, the 22a on a scroll 21,22 at least.The valve body 54 of being exerted pressure by spring members 55 moves back and forth in cylinder chamber 53 along with the pressure difference of the pressing chamber in the compression process 37 with low pressure chamber 36.Pressure difference between pressing chamber 37 and low pressure chamber 36 is when specified value is following, and valve body 54 just moves, and first communication passage 56 is communicated with second communication passage 57.In this state, the fluid in the hyperbaric chamber 45 flows into low pressure chamber 36 by two communication passage 56,57, so the pressure in the low pressure chamber 36 just rises.On the other hand, when above-mentioned pressure difference surpassed the afore mentioned rules value, valve body 54 just moved, and cut off being communicated with of first communication passage 56 and second communication passage 57.In this state, just stoped high-pressure liquid 45 to leak to low pressure chamber 36 from the hyperbaric chamber.

As mentioned above, can obtain following various effect according to the utility model.

In first model utility, after valve mechanism 51 work, when the pressure difference of pressing chamber 37 and low pressure chamber 36 is lower than specified value, hyperbaric chamber 45 is communicated with low pressure chamber 36.So above-mentioned pressure difference descends, fluid is 45 inflow low pressure chambers 36 from the hyperbaric chamber, and the pressure of low pressure chamber 36 is risen, and compressing mechanism 15 also rises from the pressure of the fluid that low pressure chamber 36 sucks.That is, in the utility model, more than the difference of the pressure of the fluid that compressing mechanism 15 sucks and the pressure in hyperbaric chamber 45 can not expand to a certain degree, the compression ratio of compressing mechanism 15 can extremely not increase.

Therefore, according to the utility model,, can avoid the excessive rising of delivery temperature even under situations such as the running of finding time, can prevent that also compression ratio from becoming excessive.Like this, just can suppress the thermal expansion of vortex circle 21b, 22b, can increasing at the surface pressure that prevents vortex circle 21b, 22b and end plate 21a, 22a in advance.And, can also reduce the wearing and tearing of end plate 21a, 22a and vortex circle 21b, 21b, and prevent the damage of these parts.Therefore, even when the running of the low drops such as turning round of finding time, also still can remain in operation.

In addition,, can avoid compressor 10 to stop repeatedly and restart according to first model utility, can be in the fault that just prevents in advance compressor 10.Further, owing to can the suppression fluid temperature too rise, can prevent because burn etc. are former thereby make lubricant oil become bad.

Also have, in the utility model, owing to suppressed to rise so high on the delivery temperature, in processes such as the running of finding time, just needn't consider the thermal expansion of vortex circle 21b, 22b and adjust the gap between end plate 21a, 22a and vortex circle 21b, the 22b very big.That is, can adjust end plate 21a, the 22a in usual when running and the gap between vortex circle 21b, the 22b very for a short time.Therefore,, the Fluid Volume that comes out from the clearance leakage between end plate 21a, 22a and vortex circle 21b, the 22b can be reduced, the efficient of compressor 10 can be improved according to the utility model.

In second model utility, valve body 54 has been subjected to the pressure difference of pressing chamber 37 with low pressure chamber 36, just moves back and forth in cylinder chamber 53 owing to the pressure of spring members 55.And because this valve body 54 is mobile, two communication passage 56,57 are changed in connection and between cutting off.Therefore,, do not need special control, can utilize simple structure that two communication passage 56,57 are changed in connection and between cutting off according to the utility model.

Description of drawings

Fig. 1 is the integrally-built sectional view of embodiment's of the present utility model scroll compressor;

Fig. 2 is the stereogram of embodiment's of the present utility model valve mechanism structure;

Fig. 3 is first communication passage and the performance plot that is communicated with cut state of second communication passage, and Fig. 3 a is a stereogram, and Fig. 3 b is a sectional view;

Fig. 4 is the performance plot of the connected state of first communication passage and second communication passage, and Fig. 4 a is a stereogram, and Fig. 4 b is a sectional view;

Fig. 5 is the performance plot of the relation between low pressure Ps and the pressure difference Δ P;

Fig. 6 is the sectional view of the valve mechanism structure among other embodiment.

Embodiment

Below, describe embodiment of the present utility model in detail with reference to accompanying drawing.

The scroll compressor of present embodiment is the compressor of compression refrigerant gas, and its connection is not represented in the drawings, makes the refrigerant gas circulation, carries out on the cryogen circuit of freeze cycle work.

As shown in Figure 1, this scroll compressor 10 has pressurized container, and promptly casing 11, has so-called fully closed structure.Hold the compressing mechanism 15 of compression refrigerant gas in the inside of this casing 11 and driven the drive motor 16 of this compressing mechanism 15.In addition, sucking pipe 18 and outlet pipe 19 also have been installed on casing 11.

Above-mentioned compressor structure 15 has fixed scroll 21 and rotation scroll 22.Two scroll 21,22 have end plate 21a, 22a respectively and vertically are arranged on Vorticose vortex circle 21b, the 22b of front one side of this end plate 21a, 22a.Vortex circle 21b, 22b on each scroll 21,22 are arranged to intermeshing state.

In the excircle end of the end plate 21a of fixed scroll 21, formed to rotation scroll 22 1 sides, i.e. the tubular that the end is arranged that protrudes of downside.The excircle end of fixed scroll 21 is fixedly mounted on the internal surface of casing 11.The vortex circle 21b of fixed scroll 21 makes from the lower surface of end plate 21a and protrudes downwards.In addition, on the head portion of vortex circle 21b, be provided with end sealing pad 21c.

On the underpart of the excircle end of the end plate 21a of fixed scroll 21, flat framework 24 has been installed in airtight mode.This framework 24 is fixed on the casing 11, simultaneously, also combines with fixed scroll 21.Like this, just, between fixed scroll 21 and framework 24, formed inner space 26.Middle body at framework 24 is provided with opening, and formed on the edge of this opening towards below, be the protuberance 28 that tubular protrudes.

Above-mentioned rotation scroll 22 is arranged in the above-mentioned inner space 26, is loaded on the framework 24.On the lower surface of the end plate 22a that rotates scroll 22, formed the bearing part 30 of the tubular that protrusion is arranged.The inside that this bearing part 30 inserts the protuberance 28 of said frame 24.

Live axle 17 runs through protuberance 28, can freely rotate.The head portion of this root live axle 17 (upper end portion) inserts in the above-mentioned bearing part 30, can freely rotate.Live axle 17 couples together the rotation scroll 22 of compressing mechanism 15 with drive motor 16.

Above-mentioned drive motor 16 has the stator 33 of compressing mechanism 15 belows that are fixed in the casing 11 and is arranged on the inboard of this stator 33, the rotor 34 that can freely rotate.Above-mentioned live axle 17 inserts in this rotor 34.When to drive motor 16 supply electric power, rotor 34 just rotates, and by live axle 17 rotary driving force is passed to rotation scroll 22.

The head portion of live axle 17 is eccentric with respect to shaft axis.Like this, when live axle 17 rotations, the just rotation on framework 24 of rotation scroll 22.In addition, rotation scroll 22 is bearing on the framework 24 by the Euclidean annulus of not representing among the figure, so it can not rotation.

The vortex circle 22b of rotation scroll 22 is arranged to protrude upward.Head portion at this vortex circle 22b is provided with end sealing pad 22c.And, the vortex circle 21b of two scroll 21,22, the surface on 22b top, the end face on end plate 21a, the 22a of oil film and another scroll 21,22 forms slip surface respectively.

In above-mentioned inner space 26, intermesh by means of vortex circle 21b, the 22b of two scroll 21,22, be separated to form pressing chamber 37.This pressing chamber 37 is spaces that vortex circle 21b, 22b and end plate 21a, the 22a by two scroll 21,22 surrounded.In addition, the vortex circle 21b in inner space 26, the outside of 22b then become low pressure chamber 36.Above-mentioned sucking pipe 18 runs through the upper end of casing 11, and the one end is at above-mentioned low pressure chamber 36 split sheds simultaneously.

On the end plate 21a of fixed scroll 21, part has formed exhaust port 41 in the central.This exhaust port 41 runs through the end plate 21a of fixed scroll 21.The refrigerant gas that is compressed by compressing mechanism 15 passes through the space of this exhaust port 41 rows to 15 tops of the compressing mechanism in casing 11.

On fixed scroll 21 and framework 24, formed the coolant channel 42 that runs through both up and down.From the refrigerant of compressing mechanism 15 discharges, by the downside of these coolant channel 42 guide frames 24.The space inner opening of framework 24 downsides of above-mentioned outlet pipe 19 in casing 11.The high-pressure refrigerant of discharging from compressing mechanism 15 goes to the derivation of the outside of casing 11 by this outlet pipe 19.

Like this, be full of the refrigerant gas that ejects in the space in the casing 11 of the scroll compressor 10 in the present embodiment 1, constituted the casing of so-called high-pressure dome type.In the space in this casing 11, except inner space 26 these parts that surrounded by fixed scroll 21 and framework 24, all constitute the hyperbaric chamber 45 that is communicated with outlet pipe 19.

As Fig. 2～shown in Figure 4, on the end plate 21a of fixed scroll 21, be provided with valve mechanism 51.On this piece end plate 21a, formed from outer peripheral surface towards the center cross-drilled hole that extends along radial direction.This cross-drilled hole uses the lid 59 that inserts from cylindrical side Monday of end plate 21a to stop up, and has constituted the cylinder chamber 53 of above-mentioned valve mechanism 51.

In addition, on the end plate 21a of fixed scroll 21, be provided with intermediate pressure communication passage 61, low pressure communication passage 62, first communication passage 56 and second communication passage 57.

One end of above-mentioned intermediate pressure communication passage 61 is at the lateral opening of the inner end (left part among Fig. 3) of cylinder chamber 53.In addition, the other end of this intermediate pressure communication passage 61 is communicated with the pressing chamber 37 of closed state in the lower surface upper shed of end plate 21a.One end of above-mentioned low pressure communication passage 62 is at the lateral opening of the outboard end (right part among Fig. 3) of cylinder chamber 53.In addition, the other end of this low pressure communication passage 62 is communicated with the low pressure chamber 36 of inner space 26 in the lower surface upper shed of end plate 21a.

One end of above-mentioned first communication passage 56 is at the lateral opening of cylinder chamber 53.Specifically, an end of first communication passage 56, the length direction central authorities position upper shed in (left side among Fig. 3) slightly in the inner part in cylinder chamber 53.In addition, the other end of first communication passage 56 is communicated with hyperbaric chamber 45 in the upper surface upper shed of end plate 21a.One end of above-mentioned second communication passage 57 is at the lateral opening of cylinder chamber 53.Specifically, an end of second communication passage 57, the position upper shed on (right side among Fig. 3) slightly in the outer part in the length direction central authorities of cylinder chamber 53.In addition, the other end of second communication passage 57 is communicated with the low pressure chamber 36 of inner space 26 in the lower surface upper shed of end plate 21a.

In above-mentioned cylinder chamber 53, insert piston 54 and spring members 55 as valve body.

Above-mentioned piston 54 has piston main body 54a and sealed member 54b, 54c, 54d.Piston main body 54a makes diameter than little cylindrical of the internal diameter of cylinder chamber 53.Therefore, between the external peripheral surface of the inner circumferential surface of cylinder chamber 53 and piston main body 54a, formed the gap.Above-mentioned sealed member 54b, 54c, 54d are embedded in the two side portions and the middle body of piston main body 54a outside respectively ringwise.

Above-mentioned piston 54 is separated into intermediate pressure space 53a, low-voltage space 53b and conversion space 53c, 53d to cylinder chamber 53.Intermediate pressure space 53a is the space that the left side of piston 54 in Fig. 3 forms.Above-mentioned intermediate pressure communication passage 61 is communicated with this intermediate pressure space 53a.Low-voltage space 53b is the right side of piston 54 in Fig. 3, i.e. the space that forms between piston 54 and the lid 59.Above-mentioned low pressure communication passage 62 is communicated with this low-voltage space 53b.Conversion is that formed space is separated with sealed member 54b, the 54d at piston two ends in the gap between the internal surface of cylinder chamber 53 and the piston main body 54a with space 53c, 53d, between intermediate pressure space 53a and low-voltage space 53b.Above-mentioned first communication passage 56 and second communication passage 57 are communicated with space 53c, 53d with conversion respectively.In addition, conversion, is separated with second conversion of space 53c and low-voltage space 53b one side first conversion of intermediate pressure space 53a one side also by means of the sealed member 54c of central authorities with space 53c, 53d with space 53d.

Above-mentioned spring members 55 is made of the helical spring that is arranged among the low-voltage space 53b.One end of this spring members 55 is crimped on the end face of piston main body 54a, and its other end then is crimped on the end face of above-mentioned lid 59, to piston 54 pressurizations, it can be moved back and forth.

Each sealed member 54b, 54c, 54d are arranged on the above-mentioned piston 54 according to following manner.

Where no matter piston 54 is gone up if being in, the sealed member 54b of intermediate pressure space 53a one side (left side on Fig. 3) is installed in the position on the piston main body 54a, on the position between the pressure communication that mediates all the time passage 61 and first communication passage 56.Therefore, even be under the state of the leftmost side among Fig. 3 in the position of piston 54, intermediate pressure communication passage 61 can not blocked by sealed parts 54b yet.

Where no matter piston 54 is gone up if being in, the sealed member 54d of low-voltage space 53b one side (right side among Fig. 3) is installed in the position on the piston main body 54a, is in all the time on the position between second communication passage 57 and the low pressure communication passage 62.Therefore, even be under the state of the rightmost side among Fig. 3 in the position of piston 54, low pressure communication passage 62 can not blocked by sealed parts 54d yet.

When piston 54 is on the position of the rightmost side among Fig. 3, the sealed member 54c of central authorities is installed in the position on the piston main body 54a, be on the position between first communication passage 56 and second communication passage 57, when piston 54 is on the position of the leftmost side among Fig. 3, the sealed member 54c of central authorities is installed in the position on the piston main body 54a, on the position between the pressure communication that the mediates passage 61 and first communication passage 56.Therefore, first communication passage 56 is at the state that is communicated with space 53c with first conversion, and changes between the state that is communicated with space 53d and change with second, and on the other hand, 57 of second communication passage are changed and are communicated with space 53d with second all the time.

In the scroll compressor 10 in the present embodiment, the refrigerant gas in the cryogen circuit flows into low pressure chamber 36 by sucking pipe 18, sucks the pressing chamber 37 from low pressure chamber 36 again.When rotation scroll 22 was rotated, pressing chamber 37 just became closed state immediately.That is, pressing chamber 37 becomes the space of sealing.Then, when rotation scroll 22 was further rotated, the volume of pressing chamber 37 was along with this rotation reduces gradually, and the refrigerant gas in pressing chamber 37 is compressed gradually.

Below, the working procedure of above-mentioned valve mechanism 51 is described with reference to Fig. 3 and Fig. 4.In the following description, so-called " left side " " right side " all is meant left and right in Fig. 3 or Fig. 4.

As mentioned above, the intermediate pressure space 53a of cylinder chamber 53 is communicated with pressing chamber 37 in the compression process under the closed state by intermediate pressure communication passage 61.Therefore, the pressure among the 53a of intermediate pressure space is the gas pressure in the pressing chamber 37 in compression process, i.e. intermediate pressure Pc.On the other hand, the low-voltage space 53b of cylinder chamber 53 is communicated with low pressure chamber 36 by low pressure communication passage 62.Therefore, the pressure of low-voltage space 53b is exactly the gas pressure in the low pressure chamber 36, i.e. low pressure Ps.

Suppose, on piston 54, be subjected to the area of the pressure (intermediate pressure Pc) of intermediate pressure space 53a, with the area of the pressure that is subjected to low-voltage space 53b (low pressure Ps) all be A.In addition, the elastic force that acts on the spring members 55 on the piston 54 is F.At this moment, for piston 54, the power above it of acting on have to the right power PcA and power PsA+F left.

At first, under the state of PcA＞PsA+F, piston 54 promptly moves to the right to low-voltage space 53b one side.When the decrement of spring members 55 increased along with moving of piston 54, the elastic force F of spring members 55 just increased gradually, and when PcA=PsA+F, piston 54 just stops to move.Then, as shown in Figure 3, under the position of the sealed member 54c of piston central authorities was in state between first communication passage 56 and second communication passage 57, first communication passage 56 just was communicated with the space 53c of the first conversion usefulness, and second communication passage 57 then is communicated with the second transformed space 53d.That is, in this state, valve mechanism 51 has cut off being communicated with between hyperbaric chamber 45 and the low pressure chamber 36.

Then, when becoming the state of PcA＜PsA+F, piston 54 promptly moves to the left to intermediate pressure space 53a one side.When the decrement of spring members 55 reduced along with moving of piston 54, the elastic force F of spring members 55 just reduced gradually, and when PcA=PsA+F, piston 54 just stops to move.Then, as shown in Figure 4, under the position of the sealed member 54c of piston central authorities was in state between the intermediate pressure communication passage 61 and first communication passage 56, first communication passage 56 and second communication passage 57 just all were communicated with the space 53d of the second conversion usefulness.That is, in this state, valve mechanism 51 makes between hyperbaric chamber 45 and the low pressure chamber 36 and is communicated with.

Like this, the magnitude relationship between the elastic force F of power (Pc-Ps) the A=Δ PA that just acted on along with the pressure difference Δ P of intermediate pressure space 53a and low-voltage space 53b of the piston 54 of valve mechanism 51 and spring members 55 and moving.In addition, the stop position of piston 54 in cylinder chamber 53 is that P is more little for Δ, just near intermediate pressure space 53a, promptly near the left side.

On the other hand, scroll compressor 10 is fluid machineries of a kind of fixedly compression ratio.Therefore, the pressing chamber 37 in the compression process under the closed state and with low pressure chamber 36 that sucking pipe 18 is communicated with in, both pressure ratios are certain.That is, the internal pressure of the pressing chamber 37 in compression process, i.e. intermediate pressure Pc, with the internal pressure of low pressure chamber 36, promptly the ratio of low pressure Ps is certain.Therefore, as shown in Figure 5, the pressure difference Δ P of pressing chamber 37 and low pressure chamber 36 and the proportionate relationship between the low pressure Ps are set up, and along with the reduction of low pressure Ps, pressure difference Δ P also reduces.And, along with the reduction of low pressure Ps pressure difference Δ P is reduced, the position of piston 54 is also near the deep of cylinder chamber 53 (near the left side).

For example, in the process of finding time to turn round etc. of refrigerating plant, as low pressure Ps when the pressure under the operating condition is low than usual, pressing chamber 37 just reduces with the pressure difference Δ P of low pressure chamber 36.When this pressure difference Δ P reduced, piston 54 just moved to the deep of cylinder chamber 53, so valve mechanism 51 just is in (referring to Fig. 4) under hyperbaric chamber 45 and the state that low pressure chamber 36 is communicated with.In this state, refrigerant gas just 45 flows into low pressure chambers 36 from the hyperbaric chamber, and the pressure of low pressure chamber 36 is risen, and the pressure of the refrigerant gas that compressing mechanism 15 sucks from low pressure chamber 36 also rises.Therefore, in processes such as the running of finding time, though the pressure of the refrigerant gas that sucks from sucking pipe 18 becomes very low, even but in this state, poor between the pressure of the gas refrigerant that pressing chamber 37 is sucked and the pressure in hyperbaric chamber 45, more than can not expanding to a certain degree, the compression ratio of compressing mechanism 15 can extremely not increase yet.

Like this,, under the situation such as the low-down running of finding time, can prevent that also compression ratio from becoming excessive, can avoid delivery temperature too to rise even the pressure of the gas refrigerant in sucking casing 11 becomes according to present embodiment.Therefore, just can suppress the thermal expansion of vortex circle 21b, 22b, just can prevent that the surface pressure between vortex circle 21b, 22b and end plate 21a, the 22a from becoming too high in advance.And, can also reduce the wearing and tearing of end plate 21a, 22a and vortex circle 21b, 22b, prevent the damage of these parts.Therefore, even when the running that low pressure like that such as find time to turn round reduces, also still can remain in operation.

In addition, can avoid compressor 10 to stop repeatedly and restart, shorten the life-spans so can prevent compressor 10.Further, owing to can suppress the too high rising of gas temperature, can prevent to become bad because of the caused lubricant oil of reasons such as burn.

In addition, owing to suppressed the too rising of delivery temperature,, do not need to adjust the gap of end plate 21a, 22a and vortex circle 21b, 22b very greatly so just needn't consider the vortex circle 21b under situation such as find time to turn round, the thermal expansion of 22b.That is, when usual running, the gap between end plate 21a, 22a and vortex circle 21b, the 22b can be very little.Therefore, according to present embodiment, can reduce the leakage rate of the gas refrigerant that from the gap of end plate 21a, 22a and vortex circle 21b, 22b, leaks, thereby can improve the efficient of compressor 10.

In addition, in the present embodiment, owing to the structure of valve mechanism 51 is that pressurization by means of spring members 55 makes piston 54 reciprocating in cylinder chamber 53, connected sum between first communication passage 56 and second communication passage 57 cuts off thereby change.Therefore, even do not control especially, also can carry out the conversion that connected sum cuts off with simple structure.

-other embodiment-

In the structure of the foregoing description, be that the connected sum that first communication passage 56 and second communication passage 57 are changed in the position of the sealed member 54c by piston main body 54a central authorities cuts off, but, also can replace it with following structure.That is, as shown in Figure 6, forming 65, two communication passage of through hole 56,57 that intersect vertically with its movement direction on piston main body 54a can be communicated with by this through hole 65, perhaps cuts off.In addition, in this structure, must insert piston main body 54a in the cylinder chamber 53 in airtight mode.

In addition, in the above-described embodiments, the spring members 55 of valve mechanism 51 is arranged among the low-voltage space 53b of cylinder chamber 53, but, also can replace a spring members 55 and be arranged among the 53a of intermediate pressure space.In this case, must be fixed on spring members 55 on the end face and piston 54 of cylinder chamber 53, make spring members 55 be in extended state all the time.

In addition, in the structure of the foregoing description, valve mechanism 51 is arranged among the end plate 21a of fixed scroll 21, but, also can replace among the end plate 22a that is arranged on rotation scroll 22.

Claims (2)

1. scroll compressor, it has the casing (11) that sucking pipe (18) and outlet pipe (19) have been installed, and have and be vertically set on a pair of scroll (21,22) that end plate (21a, 22a) is gone up Vorticose vortex circle (21b, 22b), and be arranged on the compressing mechanism (15) in the said machine casing (11)

Fluid is from the pressing chamber (37) of above-mentioned low pressure chamber (36) the suction above-mentioned compressor structure (15) that is communicated with sucking pipe (18), and fluid is arranged to the hyperbaric chamber (45) that is communicated with above-mentioned outlet pipe (19) from above-mentioned pressing chamber (37),

It is characterized in that, also have according to above-mentioned pressing chamber (37) in the compression process of under closed state, carrying out and the pressure difference between the above-mentioned low pressure chamber (36) and carry out work, only be lower than when equaling specified value the valve mechanism (51) that above-mentioned hyperbaric chamber (45) is communicated with low pressure chamber (36) in above-mentioned pressure difference.

2. scroll compressor as claimed in claim 1 is characterized in that,

Valve mechanism (51) has following various parts:

At least the end plate (21a, 22a) of a scroll in scroll (21,22) is gone up the cylinder chamber (53) that forms;

Insert in the above-mentioned cylinder chamber (53) and can freely advance and retreat, and the valve body (54) that can move according to the pressure difference of pressing chamber (37) in the compression process of under closed state, carrying out and low pressure chamber (36);

Mouthful towards above-mentioned cylinder chamber (53), first communication passage (56) that is communicated with hyperbaric chamber (45);

Mouthful towards above-mentioned cylinder chamber (53), second communication passage (57) that is communicated with low pressure chamber (36);

Above-mentioned valve body (54) is applied power, make it can above-mentioned first communication passage (56) be communicated with second communication passage (57) and the position that cuts off between reciprocating spring members (55).

Images