JP5202218B2 - Scroll type fluid machine - Google Patents

Description

  The present invention relates to a scroll fluid machine suitable for use in, for example, an air compressor, a vacuum pump, or the like.

  In general, a scroll type air compressor as a scroll type fluid machine is provided with a casing, a fixed scroll fixed to the casing and having a spiral wrap portion standing on the surface of a plate, and the fixed scroll facing the fixed scroll. An orbiting scroll having a spiral wrap portion standing on the surface of the plate body so as to overlap the wrap portion of the fixed scroll to form a plurality of compression chambers; and the compression chamber on the outermost diameter side provided in the fixed scroll And a discharge port that is provided in the fixed scroll and discharges compressed air from the compression chamber on the innermost diameter side.

  Further, a seal member is provided at the tooth tip of the wrap portion of the fixed scroll and the orbiting scroll to seal each compression chamber in sliding contact with the mating plate (for example, see Patent Document 1).

JP 2002-195175 A

  By the way, since the seal member provided at the tooth tip of the lap portion is slidably brought into contact with the plate of the other party and wears, periodic replacement is necessary. However, the installation location of the compressor is various and may be installed under adverse conditions, and it may be forced to operate severely such as repeatedly starting and stopping, so it must be sealed before the set replacement time. The member may exceed the wear limit. In this case, if the seal member exceeds the wear limit, the high-pressure compressed air on the inner diameter side leaks into the compression chamber on the low-pressure side, resulting in overcompression that widens the range of the high-pressure state. As a result, the scroll may rise in temperature due to a wide range of compression heat, causing thermal deformation, and in the case of thermal deformation, the lap portions may come into contact with each other to cause galling.

  The present invention has been made in view of the above-described problems of the prior art, and the object of the present invention is to reliably release the pressure in the compression chamber even when over-compression occurs due to wear of the seal member. It is an object of the present invention to provide a scroll type fluid machine capable of preventing damage due to ascent.

  A scroll type fluid machine according to the present invention has a fixed side member comprising a casing, a fixed scroll fixed to the casing and having a spiral wrap portion standing on the surface of a plate, and a fixed scroll of the fixed side member. A rotating scroll having a spiral wrap portion standing on the surface of the plate body and overlapping with the wrap portion of the fixed scroll to form a plurality of compression chambers; A sealing member that is slidably brought into contact with the mating plate body and seals the compression chambers; a suction port that is provided in the fixed side member and sucks fluid into the compression chamber on the outermost diameter side; and the fixed side member And a discharge port for discharging compressed fluid from the compression chamber on the innermost diameter side.

And in order to solve the subject mentioned above, the feature of the composition adopted by the invention of claim 1 is located between the suction port and the discharge port among the plurality of compression chambers in the fixed side member. When the pressure of the compression chamber exceeds a predetermined set value lower than the maximum pressure of the compression chamber on the innermost diameter side due to the flow of compressed air from the compression chamber on the innermost diameter side , the compression chamber In other words, a valve mechanism that opens the air to the atmosphere is provided.
A feature of the configuration adopted by the invention of claim 3 is that the fixed side member has a predetermined set value in which the pressure of the compression chamber located between the suction port and the discharge port among the plurality of compression chambers is predetermined. A valve mechanism that opens the compression chamber to the atmosphere when the pressure exceeds the non-return state that maintains the valve open state even when the pressure in the compression chamber drops below the set value after the valve is opened. The structure is a valve mechanism of the mold.
A feature of the configuration adopted by the invention of claim 4 is that the fixed-side member has a predetermined set value in which the pressure of the compression chamber located between the suction port and the discharge port among the plurality of compression chambers is predetermined. Provided with a valve mechanism for opening the compression chamber to the atmosphere when the pressure exceeds, a drive means for driving the orbiting scroll is provided, and when the pressure in the compression chamber with which the valve mechanism communicates exceeds a set value, The control means for stopping the operation of the drive means is provided.

  According to the present invention, when the seal member is worn and high-pressure compressed fluid leaks into the surrounding compression chamber, the valve mechanism can be opened to open the surrounding compression chamber to the atmosphere. As a result, the high temperature region of each scroll can be kept small, and the life of each lap portion can be extended.

  Hereinafter, a scroll type air compressor will be described as an example of a scroll type fluid machine according to an embodiment of the present invention, and will be described in detail with reference to the accompanying drawings.

  1 to 7 show a first embodiment according to the present invention. In FIG. 1, reference numeral 1 denotes a casing of a scroll type air compressor, and the casing 1 constitutes a fixed side member together with a fixed scroll 2 described later. The casing 1 is formed in a cylindrical shape, and a drive shaft 17 described later is rotatably supported therein.

  Reference numeral 2 denotes a fixed scroll provided on the opening side of the casing 1, and the fixed scroll 2 constitutes a fixed side member together with the casing 1. As shown in FIGS. 1 and 2, the fixed scroll 2 includes a plate body 3 called a mirror plate formed in a substantially disc shape with an axis O 1 -O 1 as a center, and a tooth bottom surface serving as a surface of the plate body 3. A spiral wrap portion 4 erected in the axial direction, a cylindrical support portion 5 surrounding the wrap portion 4 and provided on the outer diameter side of the plate body 3, and a back surface of the plate body 3. The plurality of cooling fins 6 are generally configured upright.

  Here, the wrap portion 4 is wound in a spiral shape of, for example, about 4 turns from the inner diameter side to the outer diameter side when the outermost diameter end is the winding start end and the outermost diameter end is the winding end end, for example. Has been. And the tooth tip surface of the wrap part 4 is spaced apart from the tooth bottom surface of the plate 9 of the orbiting scroll 8 which is the counterpart by a certain dimension in the axial direction.

  Further, a seal groove 4A is provided on the tooth tip surface of the wrap portion 4 along the winding direction of the wrap portion 4, and the seal groove 4A serves as a seal member slidably contacting the plate body 9 of the orbiting scroll 8. Chip seal 7 is provided. The tip seal 7 is for sealing airtightly between the wrap 4 of the fixed scroll 2 and the plate body 9 of the orbiting scroll 8 as the counterpart, for example, a resin having heat resistance, wear resistance, and slidability. It is made of material. Here, since the chip seal 7 is formed of a resin material or the like, it is gradually worn by sliding contact with the plate body 9. For this purpose, the tip seal 7 is regularly replaced.

  Reference numeral 8 denotes a turning scroll provided in the casing 1 so as to be capable of turning. The turning scroll 8 includes a substantially disc-like plate body 9 disposed to face the plate body 3 of the fixed scroll 2, and the plate body 9. A spiral wrap portion 10 erected on the bottom surface of the tooth surface, a plurality of cooling fins 11 erected on the back surface of the plate body 9, and fixed on the tip side of each cooling fin 11. The boss plate 12 is generally constituted.

  Here, the wrap portion 10 is formed in a spiral shape of, for example, about 4 turns, almost the same as the wrap portion 4 of the fixed scroll 2. And the tooth tip surface of the wrap part 10 is spaced apart from the tooth bottom surface of the plate body 3 of the fixed scroll 2 which is the counterpart by a certain dimension in the axial direction. Further, a seal groove 10A is provided on the tooth tip surface of the wrap portion 10 along the winding direction of the wrap portion 10, and a seal member that is in sliding contact with the plate body 3 of the fixed scroll 2 in the seal groove 10A. The tip seal 13 is provided. The tip seal 13 is formed in substantially the same manner as the tip seal 7 on the fixed scroll 2 side described above.

  A cylindrical boss portion 12A is integrally formed on the center side of the boss plate 12, and a crank portion 17A of a drive shaft 17 described later is rotatably connected to the boss portion 12A.

Here, the orbiting scroll 8 and the boss plate 12 are arranged at the position of the axis O2-O2 that is eccentric in the radial direction by the eccentric dimension δ of the crank portion 17A of the drive shaft 17. In this state, the wrap portion 10 of the orbiting scroll 8 is disposed so as to overlap the wrap portion 4 of the fixed scroll 2, and a plurality of compression chambers 14 to be described later are formed between these wrap portions 4, 10. Yes.

  Reference numeral 14 denotes a plurality of compression chambers formed between the wrap portion 4 of the fixed scroll 2 and the wrap portion 10 of the orbiting scroll 8. As shown in FIG. 2, these compression chambers 14 are formed with a maximum volume by surrounding air sucked from a suction port 15 described later on the outermost diameter side, and move from the outer diameter side toward the inner diameter side. Sometimes, the volume is gradually reduced while airtightness is maintained by the tip seals 7 and 13. As a result, as shown in FIG. 3, the minimum volume is obtained on the innermost diameter side immediately before being discharged from the discharge port 16.

  Here, the compression chamber 14 at an intermediate position provided between the compression chamber 14 on the outermost diameter side and the compression chamber 14 on the innermost diameter side among the plurality of compression chambers 14 will be described. In the first embodiment, for example, since each lap portion 4, 10 is set to about 4 turns, in the state shown in FIG. 2 immediately after the compression chamber 14 is formed on the outermost diameter side, the intermediate position is The compression chamber 14 (the part to which the dots are given) is divided into two stages. On the other hand, in the state shown in FIG. 3 immediately before the compressed air is discharged from the compression chamber 14 on the innermost diameter side, the compression chamber 14 at the intermediate position (the portion to which the dots are given) has one stage.

  Further, as shown in FIG. 7, the compression operation by the compression chamber 14 at the intermediate position changes the volume in the range E, and the highest reduction position at the left end of the range E is the highest compression state as the intermediate position. It becomes. Thus, each compression chamber 14 can raise the air in each compression chamber 14 to a predetermined pressure by reducing from the maximum volume on the outermost diameter side to the minimum volume on the innermost diameter side.

  A characteristic line A indicated by a solid line in FIG. 7 indicates a pressure fluctuation when the normal tip seals 7 and 13 are used. On the other hand, a characteristic line B indicated by a two-dot chain line indicates a pressure fluctuation in a state where the wear of each of the tip seals 7 and 13 has advanced to a usable limit, and when the wear exceeds the wear limit, the temperature rises. As a result, the wrap portions 4 and 10 of the scrolls 2 and 8 may be damaged.

  Reference numeral 15 denotes, for example, two suction ports provided in the fixed scroll 2. Each of the suction ports 15 opens from the outer peripheral side of the plate body 3 to the support portion 5, and communicates with the outermost diameter compression chamber 14. Yes. And the suction inlet 15 distribute | circulates the air of an atmospheric pressure state in the compression chamber 14 of the outermost diameter side through the suction filter 15A.

  On the other hand, 16 is a discharge port provided at the center position of the plate 3 of the fixed scroll 2, and the discharge port 16 communicates with the compression chamber 14 on the innermost diameter side (center side). Thereby, the discharge port 16 discharges the compressed air in the compression chamber 14 on the innermost diameter side toward an external air tank 24 via a discharge pipe 23 and the like which will be described later.

  Reference numeral 17 denotes a drive shaft supported in the casing 1 so as to be rotatable around an axis O1-O1 (see FIG. 1). The drive shaft 17 is a crank portion 17A whose tip end in the casing 1 is eccentric in the radial direction by a fixed dimension δ with respect to the axis O1-O1. A pulley 17B is attached to the projecting end side of the drive shaft 17, and the pulley 17B is connected to a drive motor 26 described later via a V-belt (not shown).

  The drive shaft 17 has a crank portion 17 </ b> A rotatably connected to the boss portion 12 </ b> A of the boss plate 12. As a result, the drive shaft 17 is rotationally driven by the drive motor 26 to cause the orbiting scroll 8 to orbit with respect to the fixed scroll 2.

  Reference numeral 18 denotes, for example, three auxiliary cranks 18 (only one is shown) provided between the outer diameter side position of the boss plate 12 and the casing 1, and each auxiliary crank 18 prevents the orbiting scroll 8 from rotating. Is.

  Reference numeral 19 denotes an outflow passage provided between the suction port 15 and the discharge port 16 and provided in the plate 3 of the fixed scroll 2. As shown in FIGS. 2 and 3, the outflow passage 19 communicates with the compression chamber 14 at the intermediate position located between the compression chamber 14 on the outermost diameter side and the compression chamber 14 on the innermost diameter side. 3 is drilled in the axial direction. In addition, a safety valve 21 described later is connected to the outflow passage 19 via a communication pipe 20.

  21 is a safety valve as a valve mechanism according to the first embodiment provided on the fixed scroll 2 so as to be connected to the communication pipe 20. When the pressure in the compression chamber 14 at the intermediate position exceeds a predetermined set value, that is, the safety valve 21, that is, the characteristic line B indicated by a two-dot chain line in FIG. 7, that is, wear of the tip seals 7 and 13. When the limit pressure fluctuation is exceeded and the high pressure range is extended to the intermediate position, the compression chamber 14 at the intermediate position is opened to the atmosphere. In addition, the safety valve 21 according to the present embodiment is formed as a non-returning type valve mechanism that maintains the valve open state even when the pressure in the compression chamber 14 drops below a set value after the valve is opened.

  The predetermined pressure set value is lower than the maximum pressure (discharge pressure) of the compression chamber 14 on the innermost diameter side, for example, and is the highest pressure permitted to the compression chamber 14 at the intermediate position, for example, compression at the intermediate position. The pressure is at a position that substantially intersects the characteristic line B at the wear limit of each of the tip seals 7 and 13 at the minimum volume position of the chamber 14. This predetermined pressure setting value is a value experimentally obtained in consideration of many other conditions.

  As shown in FIGS. 4 and 5, the safety valve 21 is provided, for example, in a cylindrical valve case 21 </ b> A closed at both ends, and provided through the bottom of the valve case 21 </ b> A in the axial direction and connected to the communication pipe 20. A valve seat cylinder 21B, an air release port 21C provided around the valve case 21A, a valve body 21D positioned in the valve case 21A and seated at the inner end of the valve seat cylinder 21B; A valve spring 21E that urges the valve body 21D to be seated on the valve seat cylinder 21B with the set pressure described above, and a return prevention mechanism 22 are configured.

  Here, the return prevention mechanism 22 constituting the safety valve 21 is provided, for example, between the valve case 21A and the inner end of the valve seat cylinder 21B. As shown in FIG. 5, when the valve element 21D is opened against the valve spring 21E, the return prevention mechanism 22 presses the stopper 22B with the pressing spring 22A, thereby causing the stopper 22B to It is sandwiched between the cylinder 21B and the valve body 21D.

  In the safety valve 21 configured in this manner, the tip seals 7 and 13 are worn and high-pressure compressed air flows from the innermost compression chamber 14 into the compression chamber 14 at the intermediate position, and the pressure in the compression chamber 14 is set to a set value. This pressure acts on the valve body 21D through the outflow passage 19 and the communication pipe 20, and the valve body 21D opens against the valve spring 21E. Thereby, the high-pressure compressed air flowing into the compression chamber 14 at the intermediate position can be released to the atmosphere. At this time, the safety valve 21 holds the stopper 22B of the return prevention mechanism 22 between the valve seat cylinder 21B and the valve body 21D so that the pressure does not increase even if the operation is continued, and the scrolls 2, 8 Temperature rise can be prevented. Moreover, it can alert | report that the tip seals 7 and 13 are a wear limit by continuing the state which does not raise a pressure.

  Reference numeral 23 denotes a discharge pipe. One end of the discharge pipe 23 is connected to the discharge port 16 of the fixed scroll 2, and the other end is connected to the air tank 24. A check valve 25 is provided in the middle of the discharge pipe 23, and the check valve 25 prevents the compressed air from flowing back from the air tank 24 to the compression chamber 14, and from the compression chamber 14. The discharge pressure is determined.

  Reference numeral 26 denotes a drive motor connected to the pulley 17B of the drive shaft 17 via a V belt (not shown) or the like. The drive motor 26 rotates the drive shaft 17 to rotate the orbiting scroll 8 with respect to the fixed scroll 2.

  The scroll type air compressor according to the first embodiment has the above-described configuration. Next, the operation of the scroll type air compressor will be described.

  First, when the drive shaft 17 is rotationally driven by the drive motor 26, the orbiting scroll 8 performs the orbiting motion with the orbiting radius δ around the axis O 1 -O 1 of the drive shaft 17 in a state where the rotation is prevented by the auxiliary crank 18. . At this time, the plurality of compression chambers 14 formed between the wrap portion 4 of the fixed scroll 2 and the wrap portion 10 of the orbiting scroll 8 are continuously reduced while moving from the outer diameter side toward the inner diameter side.

  As a result, the air sucked from the suction port 15 of the fixed scroll 2 is sequentially compressed in each compression chamber 14 and discharged as compressed air from the discharge port 16 of the fixed scroll 2, and this compressed air is discharged to the outside via the discharge pipe 23. Can be stored in the air tank 24.

  Here, in the compressing operation by the scroll type air compressor, the tip seals 7 and 13 provided at the tooth tips of the lap portions 4 and 10 are brought into sliding contact to cause wear, so that periodic replacement is necessary. However, the compressor may be installed in a hot place, or may be forced into a severe operating situation such as repeated starting and stopping. Under such operating conditions, the tip seals 7 and 13 may exceed the wear limit (characteristic line B in FIG. 7) before reaching the set replacement time.

  When the tip seals 7 and 13 exceed the wear limit in this way, the air in the high-pressure compression chamber 14 on the innermost diameter side leaks into the compression chamber 14 at the low-pressure intermediate position adjacent to the outside in the radial direction. When high-pressure compressed air leaks into the compression chamber 14 at the low-pressure intermediate position, the high-temperature region is expanded by the compression heat due to overcompression. This expansion of the high temperature region raises the temperature of the scrolls 2, 8, so that thermal deformation becomes large and the wrap portions 4, 10 are galling.

  However, according to the first embodiment, the plate 3 of the fixed scroll 2 is provided with the outflow passage 19 communicating with the compression chamber 14 located between the suction port 15 and the discharge port 16, and the outflow passage 19, a safety valve 21 is provided to open the compression chamber 14 to the atmosphere when the pressure in the compression chamber 14 exceeds a predetermined set value via the communication pipe 20.

  Therefore, when the tip seals 7 and 13 reach the wear limit and the air in the high-pressure compression chamber 14 on the innermost diameter side leaks into the compression chamber 14 at the low-pressure intermediate position, the safety valve 21 is moved to the compression chamber 14 at the intermediate position. When the pressure reaches a predetermined set value, the compression chamber 14 at the intermediate position can be opened to the atmosphere by opening the valve.

  As a result, it is possible to suppress an increase in pressure in the compression chamber 14 at the intermediate position due to wear of the tip seals 7 and 13, and it is possible to prevent the high temperature region of the scrolls 2 and 8 from expanding due to overcompression. Thereby, the deformation | transformation by the heat of each scroll 2 and 8 can be suppressed, the galling between each lap | wrap parts 4 and 10 etc. can be prevented, and these lifetimes can be extended.

  Further, the safety valve 21 is formed as a non-returning type valve mechanism that maintains the valve-opened state even when the pressure in the corresponding compression chamber 14 falls below a predetermined set value after the valve is opened. Thereby, the safety valve 21 can suppress an increase in pressure even if the operation is continued, and can prevent an increase in temperature of the scrolls 2 and 8. Further, by continuing the state in which the pressure does not increase, it is possible to notify surrounding workers and the like that the tip seals 7 and 13 are at the wear limit.

  Next, FIG. 8 shows a second embodiment of the present invention. A feature of the present embodiment is that a driving means for driving the orbiting scroll is provided, and a control means for stopping the driving means when the pressure in the compression chamber communicating with the valve mechanism exceeds a set value is provided. It is in. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  31 is a valve opening sensor provided connected to the safety valve 21. The valve opening sensor 31 electrically or mechanically detects the opening of the valve body 21D of the safety valve 21, and this detection signal is a control device described later. 32.

  Reference numeral 32 denotes a control device as control means, and the control device 32 is connected to the valve opening sensor 31 and the drive motor 26. Then, the control device 32 is based on a detection signal input from the valve opening sensor 31 when the pressure in the compression chamber 14 at the intermediate position with which the safety valve 21 communicates exceeds a set value, that is, when the safety valve 21 is opened. Thus, the operation of the drive motor 26 is stopped.

  Thus, also in the second embodiment configured as described above, it is possible to obtain substantially the same operational effects as those of the first embodiment described above. In particular, according to the second embodiment, the control device 32 is provided to stop the operation of the drive motor 26 when the pressure in the compression chamber 14 at the intermediate position exceeds a set value and the safety valve 21 is opened. Therefore, damage due to the temperature rise of each scroll 2, 8 can be prevented, and the life and reliability can be improved.

  Next, FIG. 9 and FIG. 10 show a third embodiment of the present invention. The feature of the present embodiment is that the pressure in the compression chamber at the intermediate position is detected, the electromagnetic valve is opened based on the detection result, the compression chamber is opened to the atmosphere, and the operation of the drive motor is stopped. It is in. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  Reference numeral 41 denotes an electromagnetic valve as a valve mechanism provided in place of the safety valve 21 according to the first embodiment. The electromagnetic valve 41 is normally closed and is opened by a control signal output from a control device 43 described later when the pressure in the compression chamber 14 at the intermediate position exceeds a predetermined set value. The compression chamber 14 is opened to the atmosphere.

  A pressure sensor 42 is connected to the compression chamber 14 at an intermediate position via the communication pipe 20. The pressure sensor 42 detects the pressure in the compression chamber 14 at the intermediate position, and outputs this detection signal to the control device 43.

  Reference numeral 43 denotes a control device as control means, and the control device 43 is connected to the electromagnetic valve 41, the pressure sensor 42, and the drive motor 26. The control device 43 opens the electromagnetic valve 41 to open to the atmosphere based on the detection signal input from the pressure sensor 42 when the pressure in the compression chamber 14 at the intermediate position exceeds the set value, and also drives the drive motor. 26 is stopped.

  Next, the control after the start of the scroll type air compressor by the control device 43 will be described with reference to FIG.

  In the control of the compressor, in step 1, the pressure in the compression chamber 14 at the intermediate position is detected using the detection signal of the pressure sensor 42. In step 2, it is determined whether or not the pressure at this time exceeds a preset value P. When it is determined as “YES” in step 2, since the tip seals 7 and 13 exceed the wear limit, the process moves to step 3 to open the electromagnetic valve 41, and the compression chamber 14 at the intermediate position is brought into the atmosphere. Open. Subsequently, in step 4, the operation of the drive motor 26 is stopped in order to protect the lap portions 4, 10 and the like. On the other hand, if “NO” is determined in step 2 described above, the process returns to step 1 and the same processing is repeated.

  Thus, also in the third embodiment configured as described above, it is possible to obtain substantially the same operational effects as those of the above-described embodiments.

  Next, FIG. 11 shows a fourth embodiment of the present invention. A feature of the present embodiment is that the valve mechanism is configured to open at the time of turning start of the orbiting scroll and to close after a predetermined time has elapsed. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted. Further, this embodiment has a specific configuration similar to that of the third embodiment, and a control method thereof is different. For this reason, the description about a specific structure shall be abbreviate | omitted.

  In the control of the compressor according to the fourth embodiment, when the orbiting scroll 8 of the compressor is turned, the control starts. In step 11, the electromagnetic valve 41 is opened. Thereby, since the compression chamber 14 at the intermediate position can be opened to the atmosphere, the load at the time of activation can be reduced. In step 12, a valve closing timer is started. Next, in step 13, it is determined whether or not the valve closing timer has passed a predetermined time T. This predetermined time T is, for example, the time from when the compressor is turned on until the drive motor 26 reaches substantially steady rotation. And when it determines with "YES" at step 13, since predetermined time passes and it exists in a steady operation state, it moves to step 14 and the solenoid valve 41 is closed. On the other hand, when “NO” is determined in the step 13, the same determination processing is repeated until a predetermined time elapses.

  Next, the control shifts to steps 15-18. Since steps 15-18 are the same as the control described in the third embodiment, the description thereof is omitted.

  Thus, also in the fourth embodiment configured as described above, it is possible to obtain substantially the same operational effects as those of the third embodiment described above. In particular, according to the present embodiment, the solenoid valve 41 is opened when the orbiting scroll 8 is turned, and the solenoid valve 41 is closed when a predetermined time has elapsed and a steady operation state is reached. Thereby, the compression force which becomes a big load at the time of starting can be reduced by opening the compression chamber 14 at the intermediate position to the atmosphere.

  In each embodiment, the case where the suction port 15 is provided in the fixed scroll 2 has been described as an example. However, the present invention is not limited to this, and the suction port may be provided in the casing.

  Moreover, in 1st Embodiment, the case where the safety valve 21 was provided in the fixed scroll 2 was mentioned as an example, and was demonstrated. However, the present invention is not limited to this, and a safety valve may be provided in the casing. Moreover, it is good also as a structure which provides a solenoid valve in a casing.

  Furthermore, in each embodiment, the scroll type air compressor in which the drive motor 26 is a separate body has been described as an example of the scroll type fluid machine. However, the present invention is not limited to this, and for example, the drive motor is integrated. The present invention may be applied to a scroll type air compressor, and can be widely applied to a vacuum pump or the like.

  As described in the above embodiments, according to the invention of claim 1, the seal member reaches the wear limit, and the air in the high-pressure compression chamber on the innermost diameter side leaks into the compression chamber in the low-pressure intermediate position. In this case, when the pressure in the compression chamber at the intermediate position reaches a predetermined set value, the valve mechanism can be opened to open the compression chamber at the intermediate position to the atmosphere.

  As a result, it is possible to suppress an increase in pressure in the compression chamber at the intermediate position due to wear of the seal member, and it is possible to prevent the high temperature regions of the fixed scroll and the orbiting scroll from expanding due to overcompression. Thereby, the deformation | transformation by the heat | fever of each scroll can be suppressed, the galling between each lap | wrap part etc. can be prevented, and these lifetimes can be extended.

  According to the invention of claim 2, when the valve mechanism is opened, the compression chamber at the intermediate position located between the outermost diameter side compression chamber and the innermost diameter side compression chamber can be opened to the atmosphere. .

  According to the invention of claim 3, since the valve mechanism can maintain the valve open state even when the pressure of the corresponding compression chamber is lower than the predetermined set value after the valve is opened, the operation is continued. Even in this case, an increase in pressure can be suppressed, and an increase in the temperature of each scroll can be prevented. Moreover, it can alert | report that a sealing member is a wear limit by continuing the state which does not raise a pressure.

  According to the invention of claim 4, when the pressure in the compression chamber at the intermediate position with which the valve mechanism communicates exceeds the set value, the operation of the driving means can be stopped by the control device. Thereby, the damage by the temperature rise of each scroll can be prevented, and a lifetime and reliability can be improved.

  According to the fifth aspect of the present invention, the valve mechanism can be opened when the orbiting scroll is turned on, and the valve mechanism can be closed when a predetermined time has elapsed and a steady operation state is reached. Thereby, the compression force which becomes a big load at the time of starting can be reduced by opening the compression chamber at the intermediate position to the atmosphere.

It is a longitudinal cross-sectional view which shows the scroll type air compressor applied to the 1st Embodiment of this invention. It is the cross-sectional view which looked at the fixed scroll immediately after forming the compression chamber in the outermost diameter side from the arrow II-II direction in FIG. FIG. 3 is a cross-sectional view of a fixed scroll or the like immediately before discharging compressed air from a compression chamber on the innermost diameter side to a discharge port, as viewed from the same position as in FIG. 2. It is a longitudinal cross-sectional view of the principal part expansion which shows the safety valve in FIG. 1 in a valve closing state. It is a longitudinal cross-sectional view of the principal part expansion which shows the safety valve in FIG. 1 in a valve opening state. It is a block diagram which shows the connection form of a scroll type air compressor. It is a characteristic diagram which shows the relationship between the volume of a compression chamber by the abrasion state of a chip seal, and a pressure. It is a block diagram which shows the connection form of the scroll type air compressor by 2nd Embodiment. It is a block diagram which shows the connection form of the scroll type air compressor by 3rd Embodiment. It is a flowchart which shows the control by the control apparatus in FIG. It is a flowchart which shows the control by the control apparatus of 4th Embodiment.

Explanation of symbols

1 Casing (fixed side member)
2 Fixed scroll (fixed side member)
3,9 Plate body 4,10 Lapping part 7,13 Chip seal (seal member)
8 Orbiting scroll 14 Compression chamber 15 Suction port 16 Discharge port 17 Drive shaft 19 Outflow passage 20 Communication pipe 21 Safety valve (valve mechanism)
22 Return prevention mechanism 23 Discharge piping 24 Air tank 25 Check valve 26 Drive motor (drive means)
32, 43 Control device (control means)
41 Solenoid valve (valve mechanism)
42 Pressure sensor

Claims (5)

A fixed side member comprising a casing and a fixed scroll fixed to the casing and having a spiral wrap portion standing on the surface of the plate, and a fixed side member provided opposite the fixed scroll of the fixed side member on the surface of the plate A orbiting scroll provided with a spiral wrap portion that overlaps with the wrap portion of the fixed scroll to form a plurality of compression chambers, and is slid on a mating plate provided at a tooth tip of the wrap portion of the fixed scroll and the orbiting scroll. A seal member that contacts and seals each compression chamber; a suction port that is provided in the fixed side member and sucks fluid into the compression chamber on the outermost diameter side; and the compression chamber on the innermost diameter side provided in the fixed side member In a scroll type fluid machine comprising a discharge port for discharging compressed fluid from
Among the plurality of compression chambers, the pressure of the compression chamber positioned between the suction port and the discharge port is caused to flow into the fixed side member by the compressed air from the compression chamber on the innermost diameter side flowing into the fixed side member. A scroll type fluid machine comprising a valve mechanism that opens a compression chamber to the atmosphere when a predetermined set value lower than a maximum pressure of a compression chamber on an inner diameter side is exceeded.   2. The scroll fluid machine according to claim 1, wherein the valve mechanism is configured to communicate with a compression chamber at an intermediate position located between the compression chamber on the outermost diameter side and the compression chamber on the innermost diameter side. A fixed side member comprising a casing and a fixed scroll fixed to the casing and having a spiral wrap portion standing on the surface of the plate, and a fixed side member provided opposite the fixed scroll of the fixed side member on the surface of the plate A orbiting scroll provided with a spiral wrap portion that overlaps with the wrap portion of the fixed scroll to form a plurality of compression chambers, and is slid on a mating plate provided at a tooth tip of the wrap portion of the fixed scroll and the orbiting scroll. A seal member that contacts and seals each compression chamber; a suction port that is provided in the fixed side member and sucks fluid into the compression chamber on the outermost diameter side; and the compression chamber on the innermost diameter side provided in the fixed side member In a scroll type fluid machine comprising a discharge port for discharging compressed fluid from
The fixed-side member opens the compression chamber to the atmosphere when the pressure of the compression chamber located between the suction port and the discharge port among the plurality of compression chambers exceeds a predetermined set value. Provide a valve mechanism,
The valve mechanism is a scroll type fluid machine is characterized in that the forming pressure of the compression chamber after opening is a non-return type valve mechanism for holding the open state even when lower than the set value. A fixed side member comprising a casing and a fixed scroll fixed to the casing and having a spiral wrap portion standing on the surface of the plate, and a fixed side member provided opposite the fixed scroll of the fixed side member on the surface of the plate A orbiting scroll provided with a spiral wrap portion that overlaps with the wrap portion of the fixed scroll to form a plurality of compression chambers, and is slid on a mating plate provided at a tooth tip of the wrap portion of the fixed scroll and the orbiting scroll. A seal member that contacts and seals each compression chamber; a suction port that is provided in the fixed side member and sucks fluid into the compression chamber on the outermost diameter side; and the compression chamber on the innermost diameter side provided in the fixed side member In a scroll type fluid machine comprising a discharge port for discharging compressed fluid from
The fixed-side member opens the compression chamber to the atmosphere when the pressure of the compression chamber located between the suction port and the discharge port among the plurality of compression chambers exceeds a predetermined set value. Provide a valve mechanism,
It provided a driving means for driving the orbiting scroll, wherein the valve mechanism is characterized in that a configuration in which a control means for stopping the operation of the drive means when the pressure of the compression chamber communicating exceeds a set value Scroll type fluid machine.   5. The scroll fluid machine according to claim 1, wherein the valve mechanism is configured to open when the orbiting scroll is turned and closes after a predetermined time has elapsed.

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