JP7569815B2 - Slide type switching valve and refrigeration cycle system - Google Patents

Description

The present invention relates to a slide-type switching valve used in a refrigeration cycle system such as an air conditioner, which switches the flow path of a refrigerant, and to a refrigeration cycle system.

Conventionally, a slide-type switching valve is known as a switching valve that communicates at least one pair of coupling tubes among a plurality of coupling tubes and can switch the coupling tubes to be connected (see, for example, Patent Document 1). In the slide-type switching valve described in Patent Document 1, a plurality of coupling tubes are connected to the peripheral wall of a cylindrical valve housing, and a slide valve body installed inside is slid in the axial direction to switchably connect the coupling tubes. The slide movement of the slide valve body is achieved by circulating a drive fluid through a pair of spaces that axially sandwich the slide valve body inside the valve housing. This slide-type switching valve has a plurality of thin tubes for circulating the drive fluid inside the stainless steel valve housing, and these thin tubes are made of copper.

JP 2005-121131 A

However, the above-mentioned slide-type switching valve has a problem in that the copper thin tube is easily deformed when it becomes soft due to heat during brazing, and when it is used for a long period of time in a vibrating environment, the strength of the thin tube is easily reduced due to metal fatigue.

The object of the present invention is to provide a slide-type switching valve that can suppress the deterioration of the strength of thin tubes during long-term use in a vibration environment.

The slide type switching valve of the present invention comprises a cylindrical valve housing with both ends closed, a plurality of coupling pipes connected to a peripheral wall of the valve housing so as to communicate with the interior of the valve housing, a slide valve body installed inside the valve housing to communicate with the plurality of coupling pipes and to switch a communication state by sliding in the axial direction of the valve housing, a pilot valve which circulates a drive fluid through at least one of a pair of spaces which sandwich the slide valve in the axial direction inside the valve housing to slide the slide valve body in the axial direction, and a valve body which slides in the axial direction and is connected to the pilot valve and the valve. The present invention is characterized in that the capillary tube is provided with a housing capillary made of stainless steel for connecting a housing to allow a driving fluid to flow therethrough, and a fitting capillary made of stainless steel for connecting the pilot valve to at least one of the plurality of fitting tubes to allow a driving fluid to flow therethrough, wherein a temporary welding mark as a mark of temporary welding and a brazing fixing mark as a mark of permanent fixation by brazing are formed at a connection point between the fitting capillary tube and the pilot valve, and the temporary welding mark is formed at a corner of an insertion portion of the fitting capillary tube into the pilot valve, with a welding depth that does not penetrate to an inner wall surface of the fitting capillary tube .

In this slide-type switching valve, the housing tube and the joint tube are made of stainless steel, which provides each tube with high rigidity and improved vibration resistance, preventing the strength of each tube from decreasing during long-term use in a vibrating environment.

Here, it is preferable that the valve housing is made of stainless steel and the housing capillary is directly connected to the valve housing.

With this configuration, the housing capillary and the valve housing are directly connected without an intermediate member, reducing the number of parts and lowering the production cost of the slide-type switching valve.

It is also preferable that the valve housing comprises a cylindrical valve body made of stainless steel and a pair of cap parts, each made of stainless steel, that close both end openings of the valve body, and that the housing capillary is connected to at least one of the pair of cap parts by a direct connection.

With this configuration, the valve body and cap are made of stainless steel, which allows each part to be made thinner than, for example, parts made of brass, making it possible to miniaturize the slide-type switching valve. Furthermore, the connection between the housing capillary and the cap is made between the same type of metal, so the connection can be easily made by brazing, etc.

It is also preferable that at least one of the multiple joint tubes is made of stainless steel, and that the joint tube is directly connected to the stainless steel joint tube.

With this configuration, the coupling tube and the coupling tube to be connected are made of stainless steel, which allows each part to be made thinner than, for example, those made of copper, and allows the slide-type switching valve to be made smaller. Furthermore, since the coupling tube and the coupling tube are connected between the same type of metal, the connection can be easily made by brazing, etc.

It is also preferable that the pilot valve has a pilot valve housing made of stainless steel, and that the housing capillary and the joint capillary are directly connected to the pilot valve housing.

With this configuration, the pilot valve housing is made of stainless steel, which allows the parts to be made thinner than those made of brass, for example, and allows the slide-type switching valve to be made more compact. Furthermore, the connections between the housing capillary and coupling capillary and the pilot valve housing are made between the same type of metal, so connections can be easily made by brazing, etc.

In addition, at the connection point between the housing capillary tube and the valve housing, and at the connection point between the fitting capillary tube and at least one of the multiple fitting tubes, temporary welding marks as traces of temporary welding and brazing fixing marks as traces of permanent fixation by brazing are formed, and it is preferable that the temporary welding marks at the connection point of the housing capillary tube and the connection point of the at least one capillary tube are formed at the corners of the insertion parts of the housing capillary tube and the at least one capillary tube into their respective connection destinations, with a welding depth that does not penetrate to the inner wall surfaces of the housing capillary tube and the at least one capillary tube .

With this configuration, the connections between the housing capillary tube and the valve housing, and between the fitting capillary tube and the fitting tube are temporarily secured by welding the stainless steel together before brazing, eliminating the need to position each capillary tube during brazing and reducing the number of steps required for brazing.

In addition, at the connection point between the housing capillary and the pilot valve, a temporary welding mark as a trace of temporary welding and a brazing fixing mark as a trace of permanent fixation by brazing are formed, and it is preferable that the temporary welding mark at the connection point of the housing capillary is formed at a corner of the insertion portion of the housing capillary into the pilot valve, with a welding depth that does not penetrate to the inner wall surface of the housing capillary .

With this configuration, the connections between the housing capillary tube and the coupling capillary tube and the pilot valve are temporarily secured by welding the stainless steel together before brazing, eliminating the need to position each capillary tube during brazing and reducing the number of steps required for brazing.

In addition, the inside of the valve housing is partitioned by the slide valve body into a pair of end chambers sandwiching the slide valve in the axial direction, the multiple joint pipes have a high-pressure pipe, a low-pressure pipe, and a pair of conduits, the slide valve body connects the high-pressure pipe to one of the pair of conduits and the low-pressure pipe to the other, and switches the connection destination of the high-pressure pipe and the low-pressure pipe by sliding movement, the pilot valve circulates the fluid of the high-pressure pipe to one of the pair of end chambers and the fluid of the low-pressure pipe to the other, thereby sliding the slide valve body, and the housing capillary is provided in a pair to connect the pilot valve to the pair of end chambers, and the joint capillary is provided in a pair to connect the pilot valve to the high-pressure pipe and the low-pressure pipe.

A slide-type switching valve having this configuration is a four-way switching valve that switches the communication state of four joint pipes: a high-pressure pipe, a low-pressure pipe, and a pair of conduits. Four-way switching valves are often attached to air conditioners and used for long periods of time in a vibration environment caused by vibrations from compressors and the like. With the above configuration, it is possible to suppress a decrease in the strength of each thin tube in such a four-way switching valve.

The refrigeration cycle system of the present invention is characterized by comprising a compressor that compresses a refrigerant fluid, a first heat exchanger that functions as a condenser in the cooling mode, a second heat exchanger that functions as an evaporator in the cooling mode, an expansion means that expands and reduces the pressure of the refrigerant between the first heat exchanger and the second heat exchanger, and a slide-type switching valve as the above-mentioned four-way switching valve.

This refrigeration cycle system is equipped with a slide-type switching valve as the above-mentioned four-way switching valve, which makes it possible to suppress the deterioration of the strength of each thin tube during long-term use in a vibration environment.

The slide-type switching valve and refrigeration cycle system of the present invention can provide a slide-type switching valve that can suppress deterioration of the strength of the thin tubes during long-term use in a vibration environment.

1 is a plan view of a slide type switching valve according to a first embodiment of the present invention, as viewed from a pilot valve side. 2 is a side view of the slide type switching valve shown in FIG. 1, as viewed from the direction of arrow V11 in FIG. 3 is a cross-sectional view showing a cross section of the slide type switching valve shown in FIG. 2 taken along line V12-V12 in FIG. 2. 3 is a cross-sectional view showing a cross section of the pilot valve shown in FIG. 2 taken along line V13-V13 in FIG. 2. FIG. 5 is a schematic diagram showing a refrigeration cycle system including the slide type switching valve shown in FIGS. FIG. 4 is a schematic enlarged view of a region A11 in FIG. 3 for the connection between the second housing capillary and the valve housing. 3 is a schematic enlarged view of an area A12 in FIG. 2 showing the connection between a thin tube for a low-pressure joint and an S joint tube. FIG. FIG. 5 is a cross-sectional view equivalent to that of FIG. 3 showing a slide type switching valve according to a second embodiment of the present invention.

The slide-type switching valve according to the first embodiment of the present invention will be described below with reference to Figures 1 to 7.

Figure 1 is a plan view of the slide type switching valve of the first embodiment of the present invention as viewed from the pilot valve side, and Figure 2 is a side view of the slide type switching valve shown in Figure 1 as viewed from the direction of arrow V11 in Figure 1. Also, Figure 3 is a cross-sectional view showing a cross section of the slide type switching valve shown in Figure 2 taken along line V12-V12 in Figure 2, and Figure 4 is a cross-sectional view showing a cross section of the pilot valve shown in Figure 2 taken along line V13-V13 in Figure 2. Also, Figure 5 is a schematic diagram showing a refrigeration cycle system equipped with the slide type switching valve shown in Figures 1 to 4.

As shown in Figures 1 to 5, the slide-type switching valve 10 of this embodiment is a four-way switching valve that switches the communication state of four joint pipes, and has a structure that includes a pair of pistons 2L, 2R, a connecting plate 3, a valve seat 4, and a valve body 5 within a valve housing 1.

The valve housing 1 is a cylindrical member with both ends closed, and is composed of a cylindrical section (valve body) 11 made of stainless steel and two cap sections 12L, 12R made of stainless steel. The cap sections 12L, 12R are attached to the cylindrical section 11 so as to close both end openings of the cylindrical section 11. The central axes of the cylindrical section 11 and the cap sections 12L, 12R form the axis X of the valve housing 1. A number of coupling pipes, namely D coupling pipe 13d, E coupling pipe 13e, S coupling pipe 13s, and C coupling pipe 13c, the details of which will be described later, are connected to the peripheral wall of the valve housing 1 so as to communicate with the inside of the valve housing 1.

The pair of pistons 2L, 2R, the connecting plate 3, and the valve body 5 constitute a slide valve body 6 that slides in the axial direction D11 inside the valve housing 1. This slide valve body 6 is installed inside the valve housing 1 to connect two pairs of joint pipes among the multiple joint pipes described above, and switches the joint pipes to be connected by sliding.

The pair of pistons 2L, 2R are arranged opposite each other and can move back and forth while pressing the packing 21 against the inner peripheral surface of the cylindrical portion 11. As a result, the interior of the valve housing 1 is divided by the two pistons 2L, 2R into a central high-pressure chamber 11A and two working chambers, a first working chamber 12A and a second working chamber 12B, on either side of the high-pressure chamber 11A. The first working chamber 12A and the second working chamber 12B are a pair of end chambers partitioned by the slide valve body 6 inside the valve housing 1 so as to sandwich the slide valve body 6 in the axial direction D11.

The connecting plate 3 is made of a metal plate, and is installed between the pistons 2L, 2R so that it is positioned on the axis X of the valve housing 1, and holds the valve body 5 in its center. A through hole 3a is formed in the connecting plate 3. When the pistons 2L, 2R move, the valve body 5 slides on the valve seat 4 in conjunction with the connecting plate 3, and stops at the left and right positions where the stopper plates 24 (described later) provided on the pistons 2L, 2R abut against the cap portions 12L, 12R.

The valve seat 4 is disposed in the middle of the cylindrical portion 11, and the D joint pipe 13d is attached as a high-pressure pipe that opens into the cylindrical portion 11 at a position facing the valve seat 4 in the middle of the cylindrical portion 11. In addition, the E joint pipe 13e and the C joint pipe 13c as a pair of conduits and the S joint pipe 13s as a low-pressure pipe are attached to the valve seat 4 in a straight line in the axial direction X of the valve housing 1. The valve body 5 has a bowl-shaped recess 5A formed on its inside. At the end position on the left side of FIG. 3, the valve body 5 communicates with the S joint pipe 13s and the E joint pipe 13e through the bowl-shaped recess 5A. At this time, the C joint pipe 13c communicates with the D joint pipe 13d mainly through the through hole 3a of the connecting plate 3 in the high-pressure chamber 11A. In addition, when the valve body 5 is at the right end position where the slide valve body 6 has moved to the right in FIG. 3, the S joint pipe 13s and the C joint pipe 13c are connected by the bowl-shaped recess 5A. At this time, the E joint pipe 13e is connected to the D joint pipe 13d mainly through the through hole 3a in the high pressure chamber 11A.

In the refrigeration cycle system 30 shown in FIG. 5, the D joint pipe 13d is a high-pressure pipe connected to the discharge port of the compressor 31, and the S joint pipe 13s is a low-pressure pipe connected to the suction port of the compressor 31. The C joint pipe 13c is a conduit connected to the outdoor heat exchanger 32 (first heat exchanger), and the E joint pipe 13e is a conduit connected to the indoor heat exchanger 33 (second heat exchanger). The outdoor heat exchanger 32 and the indoor heat exchanger 33 are connected via a throttling device 34 (expansion means). The refrigeration cycle system is composed of the path from the C joint pipe 13c to the outdoor heat exchanger 32, the throttling device 34, the indoor heat exchanger 33, and the E joint pipe 13e, and the path from the S joint pipe 13s to the compressor 31 and the D joint pipe 13d. Note that the refrigerant in the refrigeration cycle system contains a small amount of refrigeration oil to protect the compressor 31 and other equipment.

The pilot valve 7 is connected to the valve housing 1 via a pair of brackets 71. The pilot valve 7 causes the slide valve body 6 to slide in the axial direction D11 by circulating the drive fluid through a pair of spaces inside the valve housing 1 that sandwich the slide valve body 6 in the axial direction D11, i.e., through both the first working chamber 12A and the second working chamber 12B. In this embodiment, the pilot valve 7 causes the slide valve body 6 to slide by circulating the fluid of the D joint pipe 13d as a high-pressure pipe through one of the first working chamber 12A and the second working chamber 12B and circulating the fluid of the S joint pipe 13s as a low-pressure pipe through the other.

As shown in FIG. 4, the pilot valve 7 has a structure similar to that of the slide type switching valve 10, and is equipped with an electromagnetic actuator 73 consisting of an electromagnetic coil 731 (see FIG. 1), a plunger 732, and an attractor 733. The electromagnetic actuator 73 is operated by energizing the electromagnetic coil 731, and the pilot valve body 74 inside the cylindrical stainless steel pilot valve housing 72 is slid to switch the flow path. The pilot valve body 74 switches the communication destination of the low pressure coupling thin tube 14s that communicates with the S coupling tube 13s as a low pressure piping connected to the suction port of the compressor 31 as follows. That is, the pilot valve body 74 switches the communication destination of the low pressure coupling thin tube 14s between the first housing thin tube 14L connected to the first working chamber 12A of the slide type switching valve 10 and the second housing thin tube 14R connected to the second working chamber 12B. At the same time, the destination of the high-pressure joint thin tube 14d, which is connected to the D joint pipe 13d as a high-pressure pipe connected to the discharge port of the compressor 31, is switched between the second housing thin tube 14R and the first housing thin tube 14L. This generates a pressure difference between the pressure of the first working chamber 12A and the pressure of the second working chamber 12B to which the suction pressure and discharge pressure of the compressor 31 are introduced, and this pressure difference causes the slide valve body 6, which is partitioned by the pistons 2L and 2R, to slide in the axial direction D11 from the high-pressure side to the low-pressure side. This sliding movement switches the position of the valve body 5 in the slide valve body 6, switching the flow path of the refrigeration cycle system 30.

With the above configuration, the high-pressure refrigerant compressed by the compressor 31 flows into the main valve chamber 11A from the D joint pipe 13d, and in the cooling operation state (cooling mode), the high-pressure refrigerant flows into the outdoor heat exchanger 32 from the C joint pipe 13c. Also, in the heating operation state (heating mode) in which the position of the valve body 5 is switched, the high-pressure refrigerant flows into the indoor heat exchanger 33 from the E joint pipe 13e. That is, during cooling operation, the refrigerant discharged from the compressor 31 circulates from the C joint pipe 13c → the outdoor heat exchanger 32 → the throttling device 34 → the indoor heat exchanger 33 → the E joint pipe 13e, and the outdoor heat exchanger 32 functions as a condenser and the indoor heat exchanger 33 functions as an evaporator, performing cooling. The throttling device 34 expands the refrigerant between the outdoor heat exchanger 32 and the indoor heat exchanger 33 to reduce its pressure. During heating operation, the refrigerant is circulated in the opposite direction, with the indoor heat exchanger 33 functioning as a condenser and the outdoor heat exchanger 32 functioning as an evaporator to provide heating.

The pistons 2L, 2R of the slide-type switching valve 10 have a mirror-symmetrical structure as shown in Figure 3. Each piston 2L, 2R is equipped with a packing 21, a fixed disk 22 fixed to the connecting plate 3, a leaf spring 23, and a disk-shaped stopper plate 24. The packing 21, fixed disk 22, leaf spring 23, and stopper plate 24 are arranged coaxially around the axis X and fixed together with rivets, and the integrated pistons 2L, 2R are fixed to the connecting plate 3 with bolts.

Here, the slide type switching valve 10 is provided with the first housing capillary tube 14L and the second housing capillary tube 14R, which connect the pilot valve 7 to the first working chamber 12A and the second working chamber 12B inside the valve housing 1 and allow the driving fluid to flow, as described above. In addition, a high-pressure joint capillary tube 14d is provided, which connects the pilot valve 7 to the D joint tube 13d as a high-pressure piping and allows the high-pressure fluid of the D joint tube 13d to flow to the pilot valve 7 as a driving fluid. Furthermore, a low-pressure joint capillary tube 14s is provided, which connects the pilot valve 7 to the S joint tube 13s as a low-pressure piping and allows the low-pressure fluid of the S joint tube 13s to flow to the pilot valve 7 as a driving fluid. At this time, all of these four capillaries are stainless steel capillaries, and each end is connected to the peripheral walls of the valve housing 1, the pilot valve housing 72, the D joint tube 13d, and the S joint tube 13s, all of which are also made of stainless steel, as described below.

First, the equivalent connections between the first housing capillary tube 14L and the second housing capillary tube 14R and the valve housing 1 will be explained using the connection between the second housing capillary tube 14R and the valve housing 1 as a representative example.

Figure 6 is a schematic diagram showing an enlarged view of area A11 in Figure 3 regarding the connection between the second housing capillary tube 14R and the valve housing 1.

6, the second housing capillary tube 14R is directly connected to the cap portion 12R of the valve housing 1. Specifically, a through hole 121 for inserting a capillary tube is formed in the peripheral wall of the cap portion 12R formed in a dish shape, and the end of the second housing capillary tube 14R is inserted into this through hole 121 and connected by temporary spot welding and permanent fixation by brazing. At the connection point between the second housing capillary tube 14R and the cap portion 12R, a temporary welding mark 122 (also shown by black dots in FIG. 1) as a temporary welding mark and a brazing fixing mark 123 as a permanent fixation mark by brazing are formed. The brazing fixing mark 123 is formed in the circumferential direction of the second housing capillary tube 14R so that a part of it overlaps with the temporary welding mark 122. The connection between the first housing capillary tube 14L and the valve housing 1 is also performed in a manner similar to the above so that the temporary welding mark 122 and the brazing fixing mark 123 are formed.

Next, we will explain the connection between the high-pressure joint thin tube 14d and the D joint tube 13d, and the connection between the low-pressure joint thin tube 14s and the S joint tube 13s, which are equivalent to each other, using the latter connection as a representative example.

Figure 7 is a schematic diagram showing an enlarged view of area A12 in Figure 2 regarding the connection between the low-pressure joint thin tube 14s and the S joint tube 13s.

As shown in this Figure 7, the low pressure joint thin tube 14s is directly connected to the S joint tube 13s. Specifically, a through hole 131 for inserting a thin tube is formed in the peripheral wall of the S joint tube 13s, and the end of the low pressure joint thin tube 14s is inserted into this through hole 131 and connected by temporary spot welding and permanent fixation by brazing. At the connection point between the low pressure joint thin tube 14s and the S joint tube 13s, a temporary welding mark 132 (also shown by black dots in Figure 1) as a temporary welding mark and a brazing fixing mark 133 as a permanent fixation mark by brazing are formed. The brazing fixing mark 133 is formed around the entire circumference of the low pressure joint thin tube 14s so that a part of it overlaps with the temporary welding mark 132. The connection between the high pressure joint thin tube 14d and the D joint tube 13d is also performed in a similar manner to the above, forming a temporary welding mark 132 and a brazing fixing mark 133.

Next, the connections between the first housing capillary tube 14L, the second housing capillary tube 14R, the high pressure joint capillary tube 14d, and the low pressure joint capillary tube 14s and the pilot valve housing 72 will be described. Here, as shown in FIG. 4 as a schematic enlarged view of a cross section of area A13 as viewed from the direction of arrow V14, the connection between the second housing capillary tube 14R and the pilot valve housing 72 will be described as a representative example.

As shown in the enlarged view of FIG. 4, the second housing capillary tube 14R is directly connected to the pilot valve housing 72. First, a through hole 722 for inserting a capillary tube is formed in the pilot valve seat 721, which is a part of the peripheral wall of the pilot valve housing 72. The end of the second housing capillary tube 14R is inserted into this through hole 722 and connected by temporary spot welding and permanent fixation by brazing. At the connection point between the second housing capillary tube 14R and the pilot valve seat 721, a temporary welding mark 723 (also shown by black dots in FIG. 1) as a temporary welding mark and a brazing fixing mark 724 as a permanent fixation mark by brazing are formed. The brazing fixing mark 724 is formed around the entire circumference of the second housing capillary tube 14R so that a part of it overlaps with the temporary welding mark 723. The first housing capillary tube 14L, the high pressure fitting capillary tube 14d, and the low pressure fitting capillary tube 14s are connected to the pilot valve housing 72 in the same manner as above, so that temporary welding marks 723 and brazing marks 724 are formed. The high pressure fitting capillary tube 14d is connected to the pilot valve housing 72 at a portion of the peripheral wall of the pilot valve housing 72 that faces the pilot valve seat 721.

According to the first embodiment of the slide-type switching valve 10 and the refrigeration cycle system 30 described above, the first housing capillary tube 14L, the second housing capillary tube 14R, the high-pressure joint capillary tube 14d, and the low-pressure joint capillary tube 14s are all made of stainless steel. This provides each capillary tube with high rigidity and improved vibration resistance, and suppresses the deterioration of the strength of each capillary tube during long-term use in a vibrating environment.

The slide-type switching valve 10 of this embodiment has the configuration of a four-way switching valve that switches the communication state of four joint pipes. Four-way switching valves are often attached to air conditioning equipment, for example, and used for long periods of time in a vibration environment caused by the vibration of a compressor, etc. With the above configuration, it is possible to suppress a decrease in the strength of each thin tube in such a four-way switching valve.

In addition, in this embodiment, the valve housing 1 is made of stainless steel, and the first housing capillary tube 14L and the second housing capillary tube 14R are directly connected to the valve housing 1. With this configuration, the first housing capillary tube 14L and the second housing capillary tube 14R are directly connected to the valve housing 1 without an intermediate member, so the number of parts is reduced and the production cost of the slide type switching valve 10 can be reduced.

In this embodiment, the valve housing 1 includes a cylindrical portion 11 made of stainless steel and a pair of cap portions 12L, 12R, each made of stainless steel. The first housing capillary tube 14L is directly connected to the left cap portion 12L in FIG. 1 and FIG. 3, and the second housing capillary tube 14R is directly connected to the right cap portion 12R. With this configuration, the cylindrical portion 11 and the cap portions 12L, 12R are made of stainless steel, so that each part can be made thinner than, for example, those made of brass, and the slide type switching valve 10 can be made smaller. Furthermore, the first housing capillary tube 14L and the second housing capillary tube 14R are connected to the cap portions 12L, 12R by connecting the same metals, so that connections can be easily made by brazing or the like.

In addition, in this embodiment, the D joint tube 13d, the S joint tube 13s, the C joint tube 13c, and the E joint tube 13e are all made of stainless steel. The high-pressure joint thin tube 14d and the low-pressure joint thin tube 14s are directly connected to the D joint tube 13d and the S joint tube 13s. According to this configuration, the D joint tube 13d and the S joint tube 13s to be connected to the high-pressure joint thin tube 14d and the low-pressure joint thin tube 14s are made of stainless steel. This makes it possible to make each part thinner than, for example, those made of copper, and to reduce the size of the slide-type switching valve 10. Furthermore, since the high-pressure joint thin tube 14d and the low-pressure joint thin tube 14s are connected to the D joint tube 13d and the S joint tube 13s by connecting the same metal, the connection can be easily performed by brazing, etc.

In this embodiment, the pilot valve 7 is provided with a pilot valve housing 72 made of stainless steel. The first housing capillary tube 14L, the second housing capillary tube 14R, the high pressure joint capillary tube 14d, and the low pressure joint capillary tube 14s are directly connected to the pilot valve housing 72. With this configuration, the pilot valve housing 72 is made of stainless steel, so compared to those made of brass, for example, it is possible to make the parts thinner, and the slide type switching valve 10 can be made smaller. Furthermore, the first housing capillary tube 14L, the second housing capillary tube 14R, the high pressure joint capillary tube 14d, and the low pressure joint capillary tube 14s are connected to the pilot valve housing 72 by connecting them to the same metal, so that connections can be easily made by brazing, etc.

In addition, in this embodiment, temporary weld marks 122 and brazing marks 123 are formed at the connection points between the first housing capillary tube 14L and the second housing capillary tube 14R and the valve housing 1. Furthermore, temporary weld marks 132 and brazing marks 133 are also formed at the connection points between the high pressure joint capillary tube 14d and the low pressure joint capillary tube 14s and the D joint tube 13d and the S joint tube 13s. With this configuration, the connections between each capillary tube and its connection partner are temporarily fixed by welding stainless steel to each other before brazing, eliminating the need to position each capillary tube during brazing, and reducing the number of steps required for brazing.

In addition, in this embodiment, temporary welding marks 723 and brazing marks 724 are formed at the connection points between the first housing capillary tube 14L, the second housing capillary tube 14R, the high pressure joint capillary tube 14d, and the low pressure joint capillary tube 14s and the pilot valve 7. With this configuration, the connections between each capillary tube and the pilot valve 7 are also temporarily fixed by welding the stainless steel together before brazing, eliminating the need to position each capillary tube during brazing, and reducing the number of steps required for brazing.

This concludes the explanation of the first embodiment, and next we will explain the second embodiment with reference to FIG. 8. Note that the refrigeration cycle system of the second embodiment is the same system as the refrigeration cycle system 30 of the first embodiment shown in FIG. 5, so illustration and explanation of the refrigeration cycle system of the second embodiment will be omitted below.

Figure 8 is a cross-sectional view of a slide-type switching valve according to a second embodiment of the present invention, equivalent to that of Figure 3. In Figure 8, among the components equivalent to those of the first embodiment shown in Figure 3, those necessary for the following explanation are given the same reference numerals as in Figure 3. In the following, duplicate explanations of those equivalent components will be omitted.

The second embodiment of the slide type switching valve 50 shown in FIG. 8 is the same as the first embodiment of the slide type switching valve 10 shown in FIG. 1 to FIG. 7, except for the connection points between the first housing capillary tube 14L and the second housing capillary tube 14R and the valve housing 1. Below, the slide type switching valve 50 will be explained, focusing on the differences between the two.

In this embodiment, the first housing capillary tube 14L and the second housing capillary tube 14R made of stainless steel are directly connected to the stainless steel cylindrical portion 11 of the valve housing 1, not to the caps 52R and 52L. In addition, each connection point is near the caps 52R and 52L so that the ends of the first housing capillary tube 14L and the second housing capillary tube 14R reach the first working chamber 12A and the second working chamber 12B, which are a pair of end chambers inside the valve housing. The caps 52R and 52L are shaped to avoid interference with the ends of the first housing capillary tube 14L and the second housing capillary tube 14R that reach the first working chamber 12A and the second working chamber 12B. Below, as shown in FIG. 8 as a schematic enlarged view of area A21, the connection between the second housing capillary tube 14R and the cylindrical portion 11 will be described as a representative example.

8, a through hole 511 for inserting a thin tube is formed in the peripheral wall of the cylindrical portion 11. The end of the second housing thin tube 14R is inserted into the through hole 511 and connected by temporary spot welding and permanent fixation by brazing. At the connection point between the second housing thin tube 14R and the cylindrical portion 11, a temporary welding mark 512 as a temporary welding mark and a brazing fixing mark 513 as a permanent fixation mark by brazing are formed. The brazing fixing mark 513 is formed around the entire circumference of the second housing thin tube 14R in the circumferential direction so that a part of it overlaps with the temporary welding mark 512. The connection between the first housing thin tube 14L and the valve housing 1 is also performed in the same manner as above, so that the temporary welding mark 512 and the brazing fixing mark 513 are formed.

It goes without saying that the slide-type switching valve 50 of the second embodiment described above can also suppress the deterioration of the strength of each thin tube during long-term use in a vibration environment, just like the first embodiment described above.

The first and second embodiments described above are merely representative forms of the present invention, and the present invention is not limited to these. In other words, the present invention can be implemented with various modifications within the scope of the gist of the present invention. As long as such modifications still have the configuration of the slide-type switching valve of the present invention, they are of course included in the scope of the present invention.

For example, in the first and second embodiments described above, the slide type switching valves 10 and 50 are exemplified as a four-way switching valve that switches the communication state of four joint pipes as an example of a slide type switching valve, but the slide type switching valve is not limited to a four-way switching valve. As long as the slide type switching valve switches the communication state of a plurality of joint pipes using a slide valve body, it may be a three-way switching valve that uses a slide valve body to switch the joint pipes to be connected when a pair of joint pipes out of three joint pipes are connected. Or, it may be a two-way switching valve that uses a slide valve body to open and close between two joint pipes. The number of joint pipes in the slide type switching valve and the method of switching the communication state can be appropriately set depending on the application target of the slide type switching valve. However, as described above, by using the slide type switching valve 10 of the four-way switching valve, the effect of suppressing the decrease in strength of each thin tube can be effectively utilized.

In the first and second embodiments described above, the slide type switching valves 10 and 50 in which the first housing capillary tube 14L and the second housing capillary tube 14R are directly connected to the stainless steel valve housing 1 are exemplified as an example of a slide type switching valve. However, the slide type switching valve is not limited to this, and for example, the valve housing may be formed of a material other than stainless steel, and the housing capillary tube may be indirectly connected to the valve housing via a stainless steel connecting member, or the stainless steel housing capillary tube may be directly connected to a valve housing made of a dissimilar metal such as brass without a connecting member. However, by directly connecting the first housing capillary tube 14L and the second housing capillary tube 14R to the stainless steel valve housing 1, the product cost can be reduced, and since the connection is between the same metals, the connection can be easily performed by brazing or the like, as described above.

In the above-mentioned first and second embodiments, the valve housing 1 having a stainless steel cylindrical portion 11 and a pair of cap portions 12L, 12R is exemplified as an example of a valve housing. However, the valve housing is not limited to this, and the specific configuration and material, etc. are not important. However, as described above, by adopting a stainless steel cylindrical portion 11 and a pair of cap portions 12L, 12R, it is possible to reduce the thickness of each component, and the slide-type switching valve can be made smaller.

In the first and second embodiments described above, the D joint pipe 13d, the S joint pipe 13s, the C joint pipe 13c, and the E joint pipe 13e, all of which are made of stainless steel, are given as examples of the multiple joint pipes. However, the joint pipes are not limited to these, and their specific configurations and materials are not important. However, as described above, by using joint pipes made of stainless steel, the slide-type switching valve can be made smaller and connections can be easily made by brazing or the like.

In the above-mentioned first and second embodiments, the slide type switching valves 10 and 50 in which four thin tubes are directly connected to the stainless steel pilot valve housing 72 in the pilot valve 7 are exemplified as an example of a slide type switching valve. However, the slide type switching valve is not limited to this, and the specific configuration and material of the pilot valve are not important. However, as described above, by adopting a pilot valve 7 having a stainless steel pilot valve housing 72 and directly connecting each thin tube to the pilot valve housing 72, it is possible to reduce the size of the slide type switching valve and facilitate brazing, etc.

In the above-mentioned first and second embodiments, the slide type switching valves 10, 50 in which temporary welding marks 122, 132 and brazing marks 123, 133 are formed at the connection points between the thin tube and the valve housing 1 or the joint tube are exemplified as an example of a slide type switching valve. However, the slide type switching valve is not limited to this, and temporary welding or the like may not be performed when connecting the thin tube to the valve housing or the joint tube, and temporary welding marks may not be formed at the connection points. However, as described above, by connecting the thin tube to the valve housing 1 or the joint tube in such a way that temporary welding marks 122, 132 and brazing marks 123, 133 are formed, the brazing man-hours can be reduced.

In the above-mentioned first and second embodiments, the slide type switching valves 10 and 50 in which temporary welding marks 723 and brazing marks 724 are formed at the connection point between the thin tube and the pilot valve 7 are exemplified as an example of a slide type switching valve. However, the slide type switching valve is not limited to this, and temporary welding or the like may not be performed when connecting the thin tube and the pilot valve, and temporary welding marks may not be formed at the connection point. However, as described above, by connecting the thin tube and the pilot valve 7 in such a way that temporary welding marks 723 and brazing marks 724 are formed, the brazing man-hours can be reduced.

REFERENCE SIGNS LIST 1 valve housing 2L, 2R piston 3 connecting plate 3a through hole 4 valve seat 5 valve body 5A bowl-shaped recess 6 slide valve body 7 pilot valve 10, 50 slide-type switching valve 11 cylindrical portion 11A main valve chamber 12A first working chamber (end chamber)
12B Second working chamber (end chamber)
12L, 12R, 52L, 52R Cap portion 13c C joint tube 13d D joint tube 13e E joint tube 13s S joint tube 14L First housing capillary tube 14R Second housing capillary tube 14d High pressure joint capillary tube 14s Low pressure joint capillary tube 21 Packing 22 Fixed disc 23 Leaf spring 24 Stopper plate 30 Refrigeration cycle system 31 Compressor 32 Outdoor heat exchanger (first heat exchanger)
33 Indoor heat exchanger (second heat exchanger)
34 Throttle device (expansion means)
71 Bracket 72 Pilot valve housing 73 Electromagnetic actuator 74 Pilot valve body 121, 131, 511, 722 Through hole 122, 132, 512, 723 Temporary welding mark 123, 133, 513, 724 Brazing fixing mark 721 Pilot valve seat D11 Axial direction X Axial line

Claims (9)

a cylindrical valve housing having both ends closed;
a plurality of coupling pipes connected to a peripheral wall of the valve housing so as to communicate with the interior of the valve housing;
a slide valve body that is installed inside the valve housing to communicate with the plurality of joint pipes and that switches a communication state by sliding in an axial direction of the valve housing;
a pilot valve that causes a driving fluid to flow through at least one of a pair of spaces that sandwich the slide valve in the axial direction inside the valve housing, thereby sliding the slide valve body in the axial direction;
a stainless steel housing capillary tube for connecting the pilot valve and the valve housing to allow a driving fluid to flow;
a stainless steel coupling tube that connects the pilot valve and at least one of the plurality of coupling tubes to allow a driving fluid to flow therethrough;
Equipped with
a temporary welding mark as a mark of temporary welding and a brazing fixing mark as a mark of permanent fixing by brazing are formed at a connection portion between the coupling thin tube and the pilot valve,
a pilot valve that is inserted into the pilot valve and has a weld depth that does not penetrate to an inner wall surface of the coupling tube, the pilot valve being inserted into the pilot valve and having a weld depth that does not penetrate to an inner wall surface of the coupling tube . the valve housing is made of stainless steel;
2. The slide type switching valve according to claim 1, wherein the housing thin tube is directly connected to the valve housing. The valve housing includes a cylindrical valve body made of stainless steel, and a pair of cap portions each made of stainless steel that closes openings at both ends of the valve body,
3. The slide type switching valve according to claim 1, wherein the housing thin tube is connected to at least one of the pair of cap portions, and the connection is made by a direct connection. At least one of the plurality of joint pipes is made of stainless steel;
4. The slide type switching valve according to claim 1, wherein the joint thin tube is directly connected to a joint tube made of stainless steel. the pilot valve comprising a stainless steel pilot valve housing;
5. The slide type switching valve according to claim 1, wherein the housing thin tube and the joint thin tube are directly connected to the pilot valve housing. a temporary welding mark as a mark of temporary welding and a brazing fixing mark as a mark of permanent fixing by brazing are formed at a connection portion between the housing capillary and the valve housing and at a connection portion between the joint capillary and at least one of the plurality of joint tubes ,
A slide-type switching valve as described in any one of claims 1 to 5, characterized in that temporary welding marks at the connection points of the housing capillary and the connection points of the at least one capillary are formed at corners of the insertion portions of the housing capillary and the at least one capillary into their respective connection destinations, with a welding depth that does not penetrate to the inner wall surfaces of the housing capillary and the at least one capillary . a temporary welding mark as a mark of temporary welding and a brazing fixing mark as a mark of permanent fixing by brazing are formed at a connection portion between the housing thin tube and the pilot valve ,
7. The slide type switching valve according to claim 1, wherein a temporary welding mark at a connection point of the housing thin tube is formed at a corner of an insertion portion of the housing thin tube into the pilot valve, with a welding depth that does not penetrate to an inner wall surface of the housing thin tube . Within the valve housing, a pair of end chambers are defined by the slide valve body, the end chambers sandwiching the slide valve in the axial direction,
The plurality of joint pipes include a high pressure pipe, a low pressure pipe, and a pair of conduits,
the slide valve body connects the high-pressure pipe to one of the pair of conduits and the low-pressure pipe to the other, and switches the connection destinations of the high-pressure pipe and the low-pressure pipe by sliding movement;
the pilot valve causes the fluid in the high pressure pipe to flow through one of the pair of end chambers and the fluid in the low pressure pipe to flow through the other of the pair of end chambers, thereby sliding the slide valve body,
a pair of housing capillaries are provided to connect the pilot valve and the pair of end chambers;
The slide type switching valve according to any one of claims 1 to 7, characterized in that a pair of the thin joint tubes are provided to connect the pilot valve to the high pressure pipe and the low pressure pipe. A refrigeration cycle system comprising a compressor for compressing a fluid refrigerant, a first heat exchanger functioning as a condenser in a cooling mode, a second heat exchanger functioning as an evaporator in a cooling mode, an expansion means for expanding and reducing the pressure of the refrigerant between the first heat exchanger and the second heat exchanger, and the slide-type switching valve according to claim 8.

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