JP2605521Y2 - Diaphragm pump - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm pump used for supplying paint to a spray gun or the like.

[0002]

2. Description of the Related Art FIGS. 9 and 10 show a diaphragm pump 21 according to a conventional example. In the figure, reference numeral 23 denotes a pump main body, which is provided with a pair of working fluid chambers 25 and 27 and pump chambers 29 and 31. The working fluid chamber 25 and the pump chamber 29 are provided with a diaphragm 33.
The working fluid chamber 27 and the pump chamber 31 are partitioned by a diaphragm 35. Pump room 2
Reference numerals 9 and 31 communicate with a suction port 41 via suction check valves 37 and 38, respectively. Further, the pump chambers 29 and 31 communicate with a discharge port 47 via discharge check valves 43 and 45, respectively.

[0003] Reference numeral 49 denotes a rod accommodating portion, which communicates with the working fluid chambers 25 and 27.
In addition, the rod housing 49 has a smaller diameter at the center and larger diameters at both sides than the center. Pilot air introduction holes 48 and 50 are formed on both side portions of the rod housing 49. A center rod 51 is slidably accommodated in the rod accommodating portion 49, and gaps 53 and 55 are opened between the center rod 51 and both side portions of the rod accommodating portion 49. Center rod 51
An O-ring 57 is fitted to the center of the
Thus, the gap 53 and the gap 55 are shut off. Further, rubber packings 59 and 60 are fitted to the middle portions on both sides of the center rod 51. When the rubber packings 59 and 60 are fitted to the rod accommodating portion 49, the gaps 53 and 55 and the working fluid chambers 25 and 27 are formed. Be cut off. Center rod 51
Diaphragms 33 and 35 are attached to both ends of the.

[0004] As shown in FIG. 10, the pump body 23 is provided with a five port valve 61 represented by a JIS symbol shown in FIG. The port 1 is connected to an air compressor via a main air inlet 65. The port 2 communicates with the working fluid chamber 27, and the port 4 communicates with the working fluid chamber 25. The ports 3 and 5 communicate with the outside via a silencer 67.

The five port valve 61 supplies air to the pilot port 12 or the pilot port 14 and drives the spool 64 to drive the ports 1, 2, 3, 4, 5
Open and close. The pilot port 12 has a rod housing 49.
The pilot port 14 communicates with a pilot air introduction hole 48 formed at the bottom of the vehicle.

Next, the operation of the diaphragm pump 21 will be described. Five port valve 61 is shown in FIG.
In the state shown in (1), port 1 and port 4 are shut off, port 1 and port 2 communicate, port 2 and port 3 are shut off, and port 4 and port 5 communicate. In this state, air is supplied from the port 1 to the working fluid chamber 27 via the port 2, and the diaphragm 35 is driven in the direction A. When the diaphragm 35 is driven in the direction A,
The paint in the pump chamber 31 is pressed, and the discharge check valve 45 is discharged.
Is opened, and the paint is sent out from the discharge port 47. The center rod 51 is driven in the direction A by the operation of the diaphragm 35.

When the center rod 51 is driven in the direction A, the diaphragm 33 is accordingly driven in the direction A,
The check valve 37 for suction is opened and the paint is supplied to the pump chamber 29. The air in the working fluid chamber 25 is discharged from the silencer 67 to the outside through the ports 4 and 5. When the center rod 51 is driven in the direction A and the rubber packing 60 comes off from the rod housing 49, the air in the working fluid chamber 27 flows into the gap 55. The air flowing into the gap 55 passes through the pilot air inlet 50 and is supplied to the pilot port 14. Then, the spool 64 is driven by the air supplied to the pilot port 14, the port 1 and the port 2 are shut off, the port 1 and the port 4 communicate, the port 4 and the port 5 are shut off, and the port 2 and the port 3 are connected. It is in a state where it can be communicated.

In such a state, air is supplied from the port 1 to the working fluid chamber 25 via the port 4, and the diaphragm 33 is driven in the direction B. When the diaphragm 33 is driven in the direction B, the paint in the pump chamber 29 is pressed, the discharge check valve 43 is opened, and the paint is sent out from the discharge port 47. The center rod 51 is driven in the B direction with the operation of the diaphragm 33. When the center rod 51 is driven in the direction B, the diaphragm 35 is driven in the direction B, the suction check valve 38 is opened, and the paint is supplied to the pump chamber 31. The air in the working fluid chamber 27 passes through the port 2 and the port 3 and passes through the silencer 67.
Is discharged to the outside.

When the center rod 51 is driven in the direction B and the packing 59 comes out of the rod accommodating chamber 49, the air in the working fluid chamber 25 flows into the gap 53, passes through the pilot air introduction hole 48, and goes to the pilot port 12. Supplied. Then, the five port valve 61 is in the state shown in FIG. 10, and the above operation is repeated.

[0010]

However, in the above-mentioned conventional diaphragm pump 21, the rubber packing 59 or the rubber packing 60 comes off from the rod accommodating chamber 49, and the gap 53 between the working fluid chamber 25 and the gap 5 between the working fluid chamber 27 and the gap 5 between the working fluid chamber.
When a small amount of air flows through the air passage 5, air in the working fluid chamber 25 or the working fluid chamber 27 flows into the gap 53 or the gap 55, and is supplied to the pilot port 12 or the pilot port 14 through the air introduction hole 48 or the air introduction hole 50. Then, the spool 64 is driven.

Therefore, very little air is supplied to the pilot port 12 or the pilot port 14,
The spool 64 is driven from the stage where the air pressure is low. For this reason, the spool 64 may not be pushed to the end of the stroke, and may stop at the position where the spool 64 blocks the port 1. When the spool 64 stops at the position where the port 1 is shut off, no air is supplied to any of the ports 2 and 4, so that no air is supplied to any of the working fluid chambers 25 and 27. Therefore, since the pilot air for driving the sproll 64 is not supplied, the diaphragm pump 21 stops.

As described above, the conventional diaphragm pump is
Since the air supplied to the working fluid chamber for driving the diaphragm is also used as air for switching the five port valve, there is a problem that the diaphragm pump may suddenly stop. The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a highly reliable diaphragm pump which is not likely to stop suddenly.

[0013]

According to a first aspect of the present invention, there is provided a pump body, a pair of diaphragms provided in the pump body, a pair of pump chambers formed by the pair of diaphragms, and a working fluid. Chamber, a suction port that is connected to the pair of pump chambers via a suction check valve,
A discharge port communicated with the pair of pump chambers via a check valve for discharge, and a center provided with the pair of diaphragms connected to both ends and a rod accommodating portion formed in the pump body so as to be reciprocally movable. A rod, and a working fluid switching means for switching the direction of the working fluid supplied to the one working fluid chamber and discharged from the other working fluid chamber; and a pair of working fluid switching means provided in the working fluid switching means. In a diaphragm pump that alternately supplies and discharges a working fluid to a pilot port to operate a diaphragm, a pair of switching driving members interlocked with a reciprocating operation of the center rod, and the pair of switching driving members are driven by the operation of the pair of switching driving members. A path switching member fitted to the center rod so as to slide with respect to the center rod; and an empty space formed at an intermediate portion of the path switching member. A working fluid introduction passage provided at a position sandwiched between the pair of pilot ports, for introducing a working fluid for operating the working fluid switching unit, and a port for communicating the rod housing with outside air. When the path switching member slides in one direction from the neutral position, the working fluid introduction path, the space, and one of the pair of pilot ports communicate with each other, and the other of the pair of pilot ports A diaphragm pump is in communication with outside air through the port. According to a second aspect of the present invention, in the diaphragm pump according to the first aspect, a space portion is formed by reducing a central diameter of the path switching member, and the ports respectively correspond to a pair of pilot ports. And a diaphragm pump disposed outside the sliding range of the path switching member.

[0014]

According to the first aspect of the present invention, when the path switching member is at the neutral position, the working fluid introduction path and the pilot port are shut off, and the working fluid switching means is stopped. When the working fluid is supplied to one of the pair of working fluid chambers, the diaphragm is driven, and the center rod reciprocates, the switching driving member operates in conjunction with this, and the switching driving member causes the path switching member to operate. Is slid, the working fluid introduction path communicates with the pilot port, and the working fluid is supplied from the working fluid introduction path to the pilot port, the working fluid switching means is operated, and is supplied to one of the working fluid chambers. The direction of the working fluid discharged from the other working fluid chamber is switched.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Reference numeral 71 denotes a diaphragm pump according to an embodiment of the present invention. The diaphragm pump 71 includes a pump body 73. The pump body 73 has a pair of working fluid chambers 75 and 77 and pump chambers 79 and 81.
Is provided. The working fluid chamber 75 and the pump chamber 79 are partitioned by a diaphragm 83, and the working fluid chamber 77 and the pump chamber 81 are partitioned by a diaphragm 85. The pump chambers 79, 81 are respectively provided with suction check valves 87,
It communicates with the suction port 91 via 88. Further, the pump chambers 79 and 81 communicate with the discharge port 97 via discharge check valves 93 and 95, respectively.

Reference numeral 99 denotes a rod housing, which is in communication with the working fluid chambers 75 and 77.
Bearings 70 and 72 are attached to both ends of the rod housing 99, and the center rod 1 is attached to the bearings 70 and 72.
01 is slidably supported, and can reciprocate in the AB direction. Small diameter portions 98 and 100 having smaller diameters are formed on the center rod 101. E-shaped retaining rings 102 and 104 as switching drive members are fixed to the small diameter portions 98 and 100, respectively.
The E-shaped retaining rings 102 and 104 protrude from the peripheral surface of the center rod 101.

The center rod 101 has a path switching member 1
06 is slidably fitted. Route switching member 10
The center of 6 has a smaller diameter, and a space 108 is formed. Seal members 110 and 112 are provided at both ends of the path switching member 106. Diaphragms 83 and 85 are attached to both ends of the center rod 101. A pair of ports 141 and 143 are arranged outside the sliding range of the path switching member 106 corresponding to the pair of pilot ports 12 and 14, respectively. The ports 141 and 143 allow the rod housing 99 to communicate with the outside air.

As shown in FIG. 2, a working fluid introduction passage 130 is formed in the pump body 73.
Numeral 0 communicates with the main air inlet 115 and the rod storage chamber 99, and further communicates with the space 108 of the switching member 106. The pump body 73 has a pilot air passage 13.
1, 133 are formed, and the pilot air passages 131, 133 are arranged on both sides of the working fluid introduction passage 130. In the pump body 73, the communication paths 3c, 12c,
14c is formed. The communication path 3c communicates with the hole 3d, and the hole 3d communicates with the exhaust port 117. The communication paths 12c and 14c are connected to the pilot air passages 131 and 1 respectively.
33 respectively.

As shown in FIG. 3, the pump body 73 is provided with a five port valve 111 as a working fluid switching means represented by a JIS symbol in FIG.
The five port valve 111 is provided with the interposition member 7 shown in FIG.
0 is attached to the pump body 73 shown in FIG. Holes 1b, 2b, 3b, 4b,
5b, 12b and 14b are formed.

The hole 1b of the interposition member 70 is
Is connected to the working fluid introduction path 130. The holes 2b and 4b of the interposition member 70 are connected to the holes 2d and 4d of the pump body 73.
Are in communication with each other. Holes 3b, 5b of interposition member 70
Communicates with the communication path 3c of the pump body 73, and the holes 12b and 14b of the interposition member 70 communicate with the communication paths 12c and 14c of the pump body 73, respectively. Pump body 7
3 is connected to the five port valve 1.
It communicates with 11 port 1. The holes 2d and 4d of the pump body 73 communicate with the ports 2 and 4 of the five port valve 111, respectively. Further, the pump body 73
Are connected to the pilot ports 12 and 14, respectively.

The port 1 is connected to an air compressor via a main air inlet 115. The port 2 communicates with the working fluid chamber 77, and the port 4 communicates with the working fluid chamber 75. The ports 3 and 5 communicate with the outside via the exhaust port 117.

Next, the operation of the diaphragm pump 71 will be described. When the switching member 101 is in the neutral position as shown in FIG.
Reference numerals 1 and 133 are closed by seal members 110 and 112. When the five port valve 111 is in the state shown in FIG. 3, the ports 1 and 4 are shut off, the ports 1 and 2 are in communication, the ports 2 and 3 are shut off, and the ports 4 and 5 are in communication. In this state, air is supplied from the port 1 to the working fluid chamber 77 via the port 2, and the diaphragm 85 is driven in the direction A. When the diaphragm 85 is driven in the direction A, the paint in the pump chamber 81 is pressed, the discharge check valve 95 is opened, and the discharge port 9 is opened.
The paint is sent out from 7. The center rod 101 is driven in the direction A by the operation of the diaphragm 85.

When the center rod 101 is slid in the direction A, the diaphragm 83 is accordingly driven in the direction A. The air in the working fluid chamber 75 is discharged to the outside from the exhaust port 117 through the port 4 and the port 5. When the center rod 101 slides in the direction A, FIG.
As shown in (2), the E-shaped retaining ring 102 presses the path switching member 106 and drives the path switching member 106 in the direction A, thereby connecting the space 108 with the pilot air passage 133. And the main air inlet 11
5, air is supplied to the pilot port 14 through the space 108 and the pilot air passage 133. Then, the spool 64 is driven by the air supplied to the pilot port 14, and the ports 1 and 2 are shut off.
Port 1 and port 4 communicate, port 4 and port 5 are shut off, and port 2 and port 3 communicate.

In such a state, air is supplied from the port 1 to the working fluid chamber 75 via the port 4, and the diaphragm 83 is driven in the direction B. When the diaphragm 83 is driven in the direction B, the paint in the pump chamber 79 is pressed, the discharge check valve 93 opens, and the paint is sent out from the discharge port 97. The center rod 101 is driven in the B direction with the operation of the diaphragm 83. When the center rod 101 is driven in the direction B, the diaphragm 85 is driven in the direction B accordingly. Then, the air in the working fluid chamber 77 is discharged to the outside from the exhaust port 117 through the port 2 and the port 3.

When the center rod 101 is slid in the direction B, the E-shaped retaining ring 104 presses the path switching member 106, and
To the space 108 and the pilot air passage 13
1 is communicated. Then, air is supplied to the pilot port 12 through the main air inlet 115, the space 108, and the pilot air passage 131. The air supplied to the pilot port 12 causes the spool 6 to rotate.
4 is driven, the five-port valve 111 enters the state shown in FIG. 3, and the above operation is repeated.

As shown in FIG. 7, the path switching member 106
When it is located on the directional side, a gap is opened between the E-shaped retaining ring 104 and the end of the path switching member 106 in the A direction.
Therefore, there is a time lag between the time when the center rod 101 starts to slide in the direction B and the time when the E-shaped retaining ring 104 presses the path switching member 106. Therefore, the state in which the main air inlet 115 and the pilot air passage 133 communicate with each other via the space 108 is maintained for a certain period of time. Therefore, the air is sufficiently supplied to the pilot port 14, and the spool 64 of the five port valve 111 can be reliably driven to the end of the stroke.

Similarly, when the path switching member 106 shown in FIG. 8 is located on the B direction side, a gap is opened between the E-shaped retaining ring 102, the path switching member 106, and the end in the B direction. Therefore, there is a time lag from when the center rod 101 starts to slide in the direction A to when the E-shaped retaining ring 102 presses the path switching member 106. Therefore, the main air inlet 115 and the pilot air passage 131 are separated by the space 1
The state of communication through the line 08 is maintained for a certain period of time. Therefore, the air is sufficiently supplied to the pilot port 12, and the spool 64 of the five port valve 111 can be reliably driven to the end of the stroke. Thus, the switching of the five port valve 111 can be reliably performed, and high reliability can be obtained.

Although the embodiment of the present invention has been described in detail above, the specific configuration is not limited to this embodiment, and even if there is a change in the design without departing from the gist of the present invention, the present invention is not limited to this embodiment. Included in the invention.

[0029]

As described above, according to the present invention, it is possible to prevent the diaphragm pump from suddenly stopping, and to obtain a highly reliable diaphragm pump.

[Brief description of the drawings]

FIG. 1 is a sectional view of a diaphragm pump according to an embodiment of the present invention, taken along line CC of FIG. 3;

FIG. 2 is a sectional view of the diaphragm pump according to the embodiment of the present invention, taken along line AA of FIG. 1;

FIG. 3 is a sectional view of the diaphragm pump according to the embodiment of the present invention, taken along line BB of FIG. 1;

FIG. 4 is a plan view showing an interposition member provided in the diaphragm pump according to the embodiment of the present invention, which is viewed from an arrow D in FIG. 3;

FIG. 5 is a plan view showing a pump main body provided in the diaphragm pump according to the embodiment of the present invention, which is viewed from an arrow D in FIG. 3;

FIG. 6 is a cross-sectional view for explaining an operation of a path switching member provided in the diaphragm pump according to the embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating an operation of a path switching member provided in the diaphragm pump according to the embodiment of the present invention.

FIG. 8 is a cross-sectional view for explaining an operation of a path switching member provided in the diaphragm pump according to the embodiment of the present invention.

FIG. 9 is a sectional view of a diaphragm pump according to a conventional example.

FIG. 10 is a sectional view taken along line EE of FIG. 9;

FIG. 11 is a view showing a JIS symbol of a five port valve used for a diaphragm pump.

[Explanation of symbols]

 71 Diaphragm pump 75, 77 Working fluid chamber 79, 81 Pump chamber 83, 85 Diaphragm 87, 88 Non-return valve for suction 91 Suction port 93, 95 Non-return valve for discharge 97 Discharge port 99 Rod receiving part 101 Center rod 102, 104 E-shaped retaining ring 106 path switching member 108 space section 130 working fluid introduction path 131, 133 pilot air passage path 111 five port valve 1, 2, 4 port 12, 14 pilot port

Claims (2)

(57) [Scope of request for utility model registration] A pump body, a pair of diaphragms provided in the pump body, a pair of pump chambers and a working fluid chamber formed by being partitioned by the pair of diaphragms, and A suction port communicated via a check valve, a discharge port communicated with the pair of pump chambers via a discharge check valve, and the pair of diaphragms are connected to both ends to form the pump body. And a working fluid switching means for switching the direction of the working fluid supplied to the one working fluid chamber and discharged from the other working fluid chamber. A diaphragm pump that alternately supplies and discharges a working fluid to a pair of pilot ports provided in the working fluid switching means to operate a diaphragm; A pair of switching drive members interlocked with the reciprocating operation of the rod, a path switching member fitted to the center rod to be driven by the operation of the pair of switching drive members and slide with respect to the center rod, A space formed at an intermediate portion of the path switching member, a working fluid introduction path provided at a position sandwiched between the pair of pilot ports, and adapted to introduce a working fluid for operating the working fluid switching unit; A port for communicating the rod accommodating portion with the outside air, wherein when the path switching member slides in one direction from a neutral position, the working fluid introduction path communicates with the space and one of the pair of pilot ports. A diaphragm pump, wherein the other of the pair of pilot ports communicates with outside air via the port. 2. The diaphragm pump according to claim 1, wherein a space portion is formed by reducing the diameter of the center of the path switching member, and the ports are provided corresponding to the pair of pilot ports, respectively. And a diaphragm pump disposed outside the sliding range of the path switching member.