Air chuck

Abstract

An air chuck, a chuck unit (12) is provided with a first pressure chamber (26) and a second pressure chamber (28) arranged on both sides of a piston (16) for driving a plurality of fingers (50). A valve unit (56) is provided with: a first output air flow path (74) connected to one of the first pressure chamber and the second pressure chamber; a second output air flow path (76) connected to the other of the first pressure chamber and the second pressure chamber; a first electromagnetic valve (58) connected to the first output air flow path; and a second electromagnetic valve (60) connected to the second output air flow path. The first electromagnetic valve connects the first output air flow path to an air supply source when energized, and opens the first output air flow path to the atmosphere when not energized, and the second electromagnetic valve opens the second output air flow path to the atmosphere when energized, and connects the second output air flow path to the air supply source when not energized.

Description

Technical Field

[0001] The present invention relates to an air chuck that is installed on a robotic arm, conveying device, etc. (hereinafter referred to as "robotic arm, etc".). Background Technology

[0002] Previously, it was known to mount a workpiece-holding chuck on the tip of a robotic arm. For example, Japanese Patent Application Publication No. 2010-149224 describes a robotic arm consisting of a main body assembled to the robotic arm and a hand tip detachably mounted to the main body. A chuck for holding the workpiece is mounted on the hand tip via a cylinder.

[0003] The aforementioned robotic arm's main body includes: multiple solenoid valves required for driving the chuck; air flow paths supplying air to the input ports of each solenoid valve; and air flow paths supplying air from the output ports of each solenoid valve to the tip of the hand. Thus, in addition to enabling the main body of the hand to be compatible with a wide variety of hand tips, there is no need to configure external piping around the robotic arm for air supply.

[0004] However, in chucks using two solenoid valves and driven by air, it is necessary to prevent the workpiece from falling when the solenoid valves are de-energized due to power outages or other reasons. In this case, the method of gripping the workpiece by the chuck must be considered in two ways: gripping the workpiece by clamping it on the inside of a pair of fingers, and gripping it by expanding the pair of fingers on their outside. In particular, in chucks with fewer external air pipes, it is not easy to simply change the solenoid valves or air pipes, and it is not easy to prevent the workpiece from falling based on the gripping method. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned technical problems.

[0006] The air chuck of the present invention comprises a chuck unit having multiple fingers and a valve unit mounted on a robotic arm or the like. The chuck unit includes a first pressure chamber and a second pressure chamber, which are disposed on either side of a piston for driving the multiple fingers. The valve unit includes: a first output air path connected to one of the first and second pressure chambers; a second output air path connected to the other of the first and second pressure chambers; a first solenoid valve connected to the first output air path; and a second solenoid valve connected to the second output air path. When energized, the first solenoid valve connects the first output air path to an air supply source; when de-energized, it opens the first output air path to the atmosphere. When energized, the second solenoid valve opens the second output air path to the atmosphere; when de-energized, it connects the second output air path to an air supply source. Preferably, the chuck unit can be selectively connected to the valve unit at a first rotational position and a second rotational position at different angles around the central axis of the valve unit. In the first rotational position, the first output airflow path is connected to the first pressure chamber and the second output airflow path is connected to the second pressure chamber. In the second rotational position, the first output airflow path is connected to the second pressure chamber and the second output airflow path is connected to the first pressure chamber.

[0007] The air chuck described above can prevent workpieces from falling when the solenoid valve is not energized, such as during a power outage, and can also easily prevent workpieces from falling based on the way they are held.

[0008] Because the two solenoid valves of the air chuck of the present invention are a combination of normally closed and normally open types, it is possible to prevent the workpiece from falling when the solenoid valves are not energized, such as during a power outage. Furthermore, by selectively connecting the chuck unit to a first rotational position and a second rotational position relative to the valve unit at different angles around the central axis of the valve unit, the connection relationship between the two solenoid valves and the two pressure chambers can be switched. Therefore, it is easy to prevent the workpiece from falling based on the way it is held.

[0009] The above-described objectives, features, and advantages should be readily understood from the following description of embodiments, which are illustrated with reference to the accompanying drawings. Attached Figure Description

[0010] Figure 1 This is a front view of the air chuck according to an embodiment of the present invention.

[0011] Figure 2 yes Figure 1 Side view of the air chuck.

[0012] Figure 3 It is along Figure 1 A cross-sectional view of the air chuck along line III-III.

[0013] Figure 4 It is along Figure 2 A cross-sectional view of the air chuck along line IV-IV.

[0014] Figure 5 Observing from the prescribed direction Figure 1 A partial unfolded diagram of the air chuck components.

[0015] Figure 6 From and Figure 5 Observing from different directions Figure 1 A partial unfolded diagram of the air chuck components.

[0016] Figure 7 This refers to the case where the chuck unit is connected to the valve unit in the first rotational position. Figure 1 Fluid circuit diagram of the air chuck.

[0017] Figure 8 This refers to the case where the chuck unit is connected to the valve unit in the second rotational position. Figure 1 Fluid circuit diagram of the air chuck.

[0018] Figure 9 This indicates that the waterproof cover will be installed on Figure 1 A diagram showing the state of the air chuck.

[0019] Figure 10 It indicates a change Figure 1 A diagram showing the connection state of the air chuck unit relative to the valve unit. Detailed Implementation

[0020] In the following description, when terms relating to up and down directions are used, for convenience, they refer to the directions shown in the accompanying drawings and do not limit the actual configuration of the components. The air chuck 10 of this embodiment of the invention is composed of a chuck unit 12 and a valve unit 56.

[0021] (Structure of chuck unit 12)

[0022] like Figure 1 and Figure 2 As shown, the chuck unit 12 includes a cuboid cylinder 14, a disc-shaped connector body 36, a base 42, and a pair of finger-like members 50 for holding the workpiece. The connector body 36 is connected to the lower side of the cylinder 14, and the base 42 is connected to the upper side of the cylinder 14.

[0023] like Figure 3As shown, the cylinder body 14 has a cylinder bore 14a with openings at both ends, and a piston 16 is disposed within the cylinder bore 14a. The piston 16 consists of a main body portion 16a that slides within the cylinder bore 14a and a rod portion 16b extending upward from the main body portion 16a. A rod cover 22 is installed at the upper opening of the cylinder bore 14a, and a cover 24 is installed at the lower opening of the cylinder bore 14a.

[0024] A first pressure chamber 26 is formed between the main body 16a of the piston 16 and the cover 24, and a second pressure chamber 28 is formed between the main body 16a of the piston 16 and the rod cover 22. The cylinder body 14 has a first pressure chamber air flow path 30 communicating with the first pressure chamber 26 and a second pressure chamber air flow path 32 communicating with the second pressure chamber 28. The first pressure chamber air flow path 30 and the second pressure chamber air flow path 32 open at the lower end of the cylinder body 14.

[0025] The wide side of the cylinder body 14 has two sensor slots 14b extending from the upper end to the lower end of the cylinder body 14 (see reference). Figure 5 Magnetic sensors 34 are installed in these sensor slots 14b. These magnetic sensors 34 detect the magnetic force of the magnet 18 mounted on the piston 16. The position of the piston 16 can be detected by the magnetic sensors 34. The leads 34a of the magnetic sensors 34 extend downward from the cylinder body 14.

[0026] A pair of rods 44 configured in an L-shape are disposed on the base 42. Each rod 44 has a first end 44a formed by a forked section through a slit-like groove, and a second end 44b formed in a spherical shape. The rods 44 are rotatably supported at their central portions by a rod shaft 46 fixed to the base 42. The first end 44a of the rod 44 engages with a locking pin 20 mounted on the rod portion 16b of the piston 16.

[0027] A support member 48 supporting a pair of fingers 50 is disposed on the upper side of the base 42. The support member 48 has a pair of guide grooves 48a that guide the fingers 50 to move in a direction orthogonal to the axis of the cylinder bore 14a. The fingers 50 have a base 50a disposed between the pair of guide grooves 48a of the support member 48 and a finger 50b extending upward from the base 50a. A plurality of rolling elements 49 are disposed between the base 50a of the fingers 50 and the guide grooves 48a of the support member 48. The second end 44b of the rod 44 engages with an engagement groove 50c provided in the base 50a of the fingers 50. Furthermore, reference numeral 55a indicates a bolt for connecting the base 42 to the cylinder body 14. Reference numeral 55b indicates a bolt for connecting the support member 48 to the base 42.

[0028] When air is supplied to the first pressure chamber 26 and air is expelled from the second pressure chamber 28, the piston 16 is driven upward. This causes a pair of rods 44 to rotate in a direction away from each other at their second ends 44b, and a pair of fingers 50 to move in an opening direction. When air is supplied to the second pressure chamber 28 and air is expelled from the first pressure chamber 26, the piston 16 is driven downward. This causes a pair of rods 44 to rotate in a direction close to each other at their second ends 44b, and a pair of fingers 50 to move in a closing direction.

[0029] The first connection passage 38 and the second connection passage 40 extend through the connector body 36 in the vertical direction. The first connection passage 38 is connected to the air flow path 30 of the first pressure chamber of the cylinder 14, and the second connection passage 40 is connected to the air flow path 32 of the second pressure chamber of the cylinder 14. In addition, the lead insertion hole 36a through which the lead 34a of the magnetic sensor 34 is inserted extends through the connector body 36 in the vertical direction.

[0030] The first bolt 52 is inserted into the first bolt insertion hole 36b of the connector body 36 and screwed into the threaded hole 14c at the bottom of the cylinder body 14. Thus, the connector body 36 is connected to the cylinder body 14 (see reference). Figure 4 Furthermore, reference numerals 94a and 94b indicate the pins and pin holes used for positioning when the connector body 36 is connected to the cylinder body 14.

[0031] like Figure 5 As shown, the connector body 36 has a total of four second bolt insertion holes 36c near its outer periphery. The second bolt insertion holes 36c are arranged at 90-degree intervals around the central axis CL of the connector body 36. When the connector body 36 is connected to the cylinder 14, the second bolt insertion holes 36c are not covered by the cylinder 14.

[0032] (Structure of valve unit 56)

[0033] like Figure 5 and Figure 6 As shown, the valve unit 56 includes a valve unit body 62 equipped with a first solenoid valve 58 and a second solenoid valve 60, and a disc-shaped adapter 92 connected to the lower side of the valve unit body 62. The valve unit body 62 has a cylindrical outer wall portion 64, a flow path block portion 70 on the inner side of the outer wall portion 64, an upper plate portion 88, and a lower plate portion 90 on the lower side of the flow path block portion 70. The upper plate portion 88 traverses the flow path block portion 70 on the inner side of the outer wall portion 64. The adapter 92 is a component for mounting to a robotic arm or the like (not shown).

[0034] The outer wall portion 64 has a rectangular first opening 64a. The outer wall portion 64 has a second opening 64b on the opposite side of the first opening 64a, separated by the central axis CL of the valve unit 56 (which is the same as the central axis CL of the connector body 36). The flow path block portion 70 has a flat solenoid valve mating surface 72 facing the first opening 64a. The first solenoid valve 58 and the second solenoid valve 60 are mounted on this solenoid valve mating surface 72 and can be installed and removed through the first opening 64a.

[0035] The flow path block 70 includes a first output air flow path 74 and a second output air flow path 76. One end of the first output air flow path 74 opens on the upper surface of the flow path block 70, and the other end opens on the solenoid valve mating surface 72. Similarly, one end of the second output air flow path 76 opens on the upper surface of the flow path block 70, and the other end opens on the solenoid valve mating surface 72. Furthermore, in Figure 5 In the diagram, the openings of the first output air flow path 74 and the second output air flow path 76 in the solenoid valve mating surface 72 are omitted. Reference numeral 73 indicates the threaded hole for mounting the first solenoid valve 58 and the second solenoid valve 60.

[0036] As described below, one end of the first output airflow path 74 is connected to one of the first connection passage 38 and the second connection passage 40 of the connector body 36. Additionally, one end of the second output airflow path 76 is connected to the other of the first connection passage 38 and the second connection passage 40 of the connector body 36. Figure 3 This indicates the state when the first output airflow path 74 is connected to the first connection path 38 and the second output airflow path 76 is connected to the second connection path 40.

[0037] Additionally, the flow path block 70 includes a supply air flow path 78 consisting of a general flow path 78a, a first branch flow path 78b, and a second branch flow path 78c (see reference). Figure 7 One end of the general flow path 78a opens on the side of the flow path block portion 70, located opposite the solenoid valve mating surface 72. A supply port 66 (see reference) is installed at this opening. Figure 6 The first branch flow path 78b and the second branch flow path 78c branch from the general flow path 78a and open at the solenoid valve mating surface 72. Air is supplied to the supply port 66 from an air supply source not shown in the figure. Furthermore, in Figure 5 In the middle, the openings of the first branch flow path 78b and the second branch flow path 78c in the solenoid valve mating surface 72 are omitted.

[0038] The flow path block 70 also includes a first exhaust air flow path 80 and a second exhaust air flow path 82. One end of the first exhaust air flow path 80 opens at the solenoid valve mating surface 72, and the other end opens on the side of the flow path block 70 opposite to the second opening 64b. Similarly, one end of the second exhaust air flow path 82 opens at the solenoid valve mating surface 72, and the other end opens in the flow path block 70 opposite to the second opening 64b. A first exhaust port 84 equipped with a variable throttle valve is connected to the other end of the first exhaust air flow path 80, and a second exhaust port 86 equipped with a variable throttle valve is connected to the other end of the second exhaust air flow path 82 (see reference). Figure 4 In addition, in Figure 5 In the middle, the openings of the first exhaust air path 80 and the second exhaust air path 82 in the solenoid valve mating surface 72 are omitted.

[0039] like Figure 7 As shown, the first solenoid valve 58 and the second solenoid valve 60 constitute a two-position, three-port switching valve. The first port 58a of the first solenoid valve 58 is connected to the first output air flow path 74. The second port 58b of the first solenoid valve 58 is connected to the first branch flow path 78b of the supply air flow path 78. The third port 58c of the first solenoid valve 58 is connected to the first exhaust air flow path 80. The first port 60a of the second solenoid valve 60 is connected to the second output air flow path 76. The second port 60b of the second solenoid valve 60 is connected to the second branch flow path 78c of the supply air flow path 78. The third port 60c of the second solenoid valve 60 is connected to the second exhaust air flow path 82.

[0040] When energized, the first solenoid valve 58 connects the first port 58a to the second port 58b, and when de-energized, it connects the first port 58a to the third port 58c. That is, the first solenoid valve 58 is a normally closed solenoid valve that connects the first output air flow path 74 to the air supply source when energized and opens the first output air flow path 74 to the atmosphere when de-energized.

[0041] On the other hand, when the second solenoid valve 60 is energized, it connects the first port 60a to the third port 60c, and when it is not energized, it connects the first port 60a to the second port 60b. That is, the second solenoid valve 60 is a normally open solenoid valve that opens the second output air flow path 76 to the atmosphere when energized and connects the second output air flow path 76 to the air supply source when not energized.

[0042] The outer wall portion 64 has an electrical connector 68 located near the supply port 66. Leads 58d supplying power to the first solenoid valve 58 and 60d supplying power to the second solenoid valve 60 are connected to the electrical connector 68. Additionally, the lead 34a of the magnetic sensor 34, extending downward from the opening 88a of the upper plate portion 88, is also connected to the electrical connector 68. Furthermore, reference numeral 95 indicates a bolt used to connect the adapter 92 to the valve unit body 62.

[0043] like Figure 9 As shown, a cylindrical waterproof cover 98 covering the first opening 64a is installed on the cylindrical outer wall portion 64 of the valve unit body 62. The waterproof cover 98 protects the first solenoid valve 58, the second solenoid valve 60, etc. In addition, the waterproof cover 98 has an opening 98a so as not to cover the first exhaust port 84 and the second exhaust port 86.

[0044] (Connection structure between chuck unit 12 and valve unit 56)

[0045] like Figure 5 As shown, the upper plate portion 88 of the valve unit body 62 has a total of four second bolt mounting holes 88b near the outer wall portion 64. The second bolt mounting holes 88b are arranged at 90-degree intervals around the central axis of the valve unit 56. Second bolts 54 are inserted from the upper side of the connector body 36 of the chuck unit 12 through the second bolt insertion hole 36c of the connector body 36 and screwed into the second bolt mounting holes 88b of the upper plate portion 88. Thus, the connector body 36 is connected to the valve unit body 62. That is, the chuck unit 12 is connected to the valve unit 56 by four second bolts 54.

[0046] The chuck unit 12 can be connected to the valve unit 56 at two positions with an angle difference of 180 degrees around the central axis CL of the valve unit 56 (see reference). Figure 10 Hereinafter, these positions will be referred to as the "first rotational position" and the "second rotational position". In this embodiment, the chuck unit 12 is connected to the valve unit 56 by four second bolts 54 arranged at 90-degree intervals. However, other connection methods are possible as long as the chuck unit 12 can be connected relative to the valve unit 56 at positions differing by 180 degrees. Furthermore, reference numerals 96a and 96b indicate the pins and pin holes used for positioning when the connector body 36 is connected to the valve unit body 62.

[0047] In the first rotational position, the first output air flow path 74 of the flow path block portion 70 of the valve unit body 62 is connected to the first connection passage 38 of the connector body 36 of the chuck unit 12. Additionally, the second output air flow path 76 of the flow path block portion 70 of the valve unit body 62 is connected to the second connection passage 40 of the connector body 36 of the chuck unit 12 (see reference). Figure 7On the other hand, in the second rotation position, the first output air flow path 74 of the flow path block portion 70 of the valve unit body 62 is connected to the second connection passage 40 of the connector body 36 of the chuck unit 12. Additionally, the second output air flow path 76 of the flow path block portion 70 of the valve unit body 62 is connected to the first connection passage 38 of the connector body 36 of the chuck unit 12 (see reference). Figure 8 ).

[0048] (Function when connected in the first rotational position)

[0049] Reference Figure 7 The function of the air chuck 10 when the chuck unit 12 is connected to the valve unit 56 in the first rotational position will be described. Furthermore, Figure 7 The fluid circuit diagram shows the state where the first solenoid valve 58 and the second solenoid valve 60 are not energized. Additionally, in Figure 7 In the diagram, reference symbol P1 indicates the connection point between the first output airflow path 74 and the first connection passage 38, and reference symbol P2 indicates the connection point between the second output airflow path 76 and the second connection passage 40.

[0050] When force is applied in the direction that opens the pair of fingers 50, the first solenoid valve 58 and the second solenoid valve 60 are energized. By energizing the first solenoid valve 58, air from the supply port 66 reaches the second port 58b of the first solenoid valve 58 through the supply air flow path 78 of the flow path block 70. Subsequently, this air is supplied from the first port 58a of the first solenoid valve 58 through the first output air flow path 74 of the flow path block 70, and further through the first connection passage 38 of the connector body 36 and the first pressure chamber air flow path 30 of the cylinder body 14 to the first pressure chamber 26.

[0051] Furthermore, by energizing the second solenoid valve 60, air in the second pressure chamber 28 reaches the first port 60a of the second solenoid valve 60 through the second pressure chamber air flow path 32 of the cylinder body 14, the second connection passage 40 of the connector body 36, and the second output air flow path 76 of the flow path block 70. Subsequently, this air is exhausted from the third port 60c of the second solenoid valve 60 through the second exhaust air flow path 82 and from the second exhaust port 86. Thus, since air is supplied to the first pressure chamber 26 and air is exhausted from the second pressure chamber 28, the pair of fingers 50 are driven in the opening direction. Since the second exhaust port 86 is equipped with a variable throttle valve, the speed at which the pair of fingers 50 move in the opening direction can be adjusted.

[0052] When force is applied in the direction of closing the pair of fingers 50, energizing the first solenoid valve 58 and the second solenoid valve 60 is stopped. By stopping the energizing of the second solenoid valve 60, air from the supply port 66 reaches the second port 60b of the second solenoid valve 60 through the supply air passage 78 of the flow path block 70. Subsequently, the air flows from the first port 60a of the second solenoid valve 60 through the second output air flow path 76 of the flow path block 70. The air is further supplied to the second pressure chamber 28 through the second connection passage 40 of the connector body 36 and the second pressure chamber air flow path 32 of the cylinder body 14.

[0053] Furthermore, by stopping the energization of the first solenoid valve 58, the air in the first pressure chamber 26 reaches the first port 58a of the first solenoid valve 58 through the first pressure chamber air flow path 30 of the cylinder body 14, the first connection passage 38 of the connector body 36, and the first output air flow path 74 of the flow path block 70. Subsequently, this air is exhausted from the third port 58c of the first solenoid valve 58 through the first exhaust air flow path 80 and from the first exhaust port 84. Thus, since air is supplied to the second pressure chamber 28 and the air in the first pressure chamber 26 is exhausted, the pair of fingers 50 are driven in the closing direction. Since the first exhaust port 84 is equipped with a variable throttle valve, the speed at which the pair of fingers 50 move in the closing direction can be adjusted.

[0054] The air chuck 10 is mounted on a robotic arm (not shown) with the fingers 50 facing downwards. When holding a workpiece by gripping it on the inside of the pair of fingers 50, as described above, the chuck unit 12 can be connected to the valve unit 56 in the first rotational position. In the absence of power, such as during a power outage, the pair of fingers 50 are driven in the closed direction, thus preventing the workpiece from falling.

[0055] (Function when connected in the second rotational position)

[0056] Next, refer to Figure 8 The function of the air chuck 10 when the chuck unit 12 is connected to the valve unit 56 in the second rotational position will be described. Furthermore, Figure 8 The fluid circuit diagram shows the state where the first solenoid valve 58 and the second solenoid valve 60 are not energized. Additionally, in Figure 8 In the diagram, reference symbol P3 indicates the connection point between the second output air flow path 76 and the first connection passage 38, and reference symbol P4 indicates the connection point between the first output air flow path 74 and the second connection passage 40.

[0057] When force is applied in the direction that opens the pair of fingers 50, energizing the first solenoid valve 58 and the second solenoid valve 60 is stopped. By stopping the energizing of the second solenoid valve 60, air from the supply port 66 reaches the second port 60b of the second solenoid valve 60 through the supply air flow path 78 of the flow path block 70. Subsequently, the air flows from the first port 60a of the second solenoid valve 60 through the second output air flow path 76 of the flow path block 70. The air is further supplied to the first pressure chamber 26 through the first connection passage 38 of the connector body 36 and the first pressure chamber air flow path 30 of the cylinder body 14.

[0058] Furthermore, by stopping the energization of the first solenoid valve 58, the air in the second pressure chamber 28 reaches the first port 58a of the first solenoid valve 58 through the second pressure chamber air flow path 32 of the cylinder body 14, the second connection passage 40 of the connector body 36, and the first output air flow path 74 of the flow path block 70. Subsequently, this air is exhausted from the third port 58c of the first solenoid valve 58 through the first exhaust air flow path 80 and from the first exhaust port 84. Thus, since air is supplied to the first pressure chamber 26 and the air in the second pressure chamber 28 is exhausted, the pair of fingers 50 are driven in the opening direction. Since the first exhaust port 84 is equipped with a variable throttle valve, the speed at which the pair of fingers 50 move in the opening direction can be adjusted.

[0059] When force is applied in the direction of closing the pair of fingers 50, the first solenoid valve 58 and the second solenoid valve 60 are energized. By energizing the first solenoid valve 58, air from the supply port 66 reaches the second port 58b of the first solenoid valve 58 through the supply air passage 78 of the flow path block 70. Subsequently, this air flows from the first port 58a of the first solenoid valve 58 through the first output air flow path 74 of the flow path block 70. The air is further supplied to the second pressure chamber 28 through the second connection passage 40 of the connector body 36 and the second pressure chamber air flow path 32 of the cylinder body 14.

[0060] Furthermore, by energizing the second solenoid valve 60, air in the first pressure chamber 26 reaches the first port 60a of the second solenoid valve 60 through the first pressure chamber air flow path 30 of the cylinder body 14, the first connection passage 38 of the connector body 36, and the first output air flow path 74 of the flow path block 70. Subsequently, this air is exhausted from the third port 60c of the second solenoid valve 60 through the second exhaust air flow path 82 and from the second exhaust port 86. Thus, since air is supplied to the second pressure chamber 28 and the air in the first pressure chamber 26 is exhausted, the pair of fingers 50 are driven in the closing direction. Since the second exhaust port 86 is equipped with a variable throttle valve, the speed at which the pair of fingers 50 move in the closing direction can be adjusted.

[0061] The air chuck 10 is mounted on a robotic arm (not shown) with the fingers 50 facing downwards. When the pair of fingers 50 are expanded to grip the workpiece from their outer sides, as described above, the chuck unit 12 is connected to the valve unit 56 in the second rotational position. In the absence of power, such as during a power outage, the workpiece is prevented from falling because the pair of fingers 50 are driven in the opening direction.

[0062] According to the air chuck 10 of this embodiment, the first solenoid valve 58 and the second solenoid valve 60 are a combination of normally closed and normally open types. Therefore, it is possible to prevent the workpiece from falling when the first solenoid valve 58 and the second solenoid valve 60 are not energized, such as during a power outage. In addition, the chuck unit 12 can be selectively connected to the valve unit 56 at a first rotational position and a second rotational position with different angles around the central axis CL of the valve unit 56. Therefore, since the connection relationship between the first solenoid valve 58 and the second solenoid valve 60 and the first pressure chamber 26 and the second pressure chamber 28 can be switched, it is easy to prevent the workpiece from falling based on the way the workpiece is held.

[0063] In this embodiment, the air chuck 10 has a structure having a pair of fingers 50 (two fingers 50). However, it may also have a structure having three or more fingers, for example, in which multiple fingers are arranged at equal angles on the same circumference when viewed from a predetermined direction.

[0064] The present invention is not limited to the embodiments described above, and various structures can be adopted without departing from the spirit of the present invention.

Claims

1. An air chuck (10), comprising a chuck unit (12) having a plurality of fingers (50) and a valve unit (56) mounted on a robotic arm, characterized in that, The chuck unit includes a first pressure chamber (26) and a second pressure chamber (28), which are disposed on both sides of a piston (16) for driving the plurality of fingers. The valve unit includes: a first output air path (74) connected to one of the first and second pressure chambers; a second output air path (76) connected to the other of the first and second pressure chambers; a first solenoid valve (58) connected to the first output air path; and a second solenoid valve (60) connected to the second output air path. When energized, the first solenoid valve connects the first output air path to an air supply source, and when de-energized, it opens the first output air path to the atmosphere. When energized, the second solenoid valve opens the second output air path to the atmosphere, and when de-energized, it connects the second output air path to an air supply source. The chuck unit can be selectively connected to the valve unit at a first rotational position and a second rotational position with different angles around the central axis of the valve unit. In the first rotational position, the first output air flow path is connected to the first pressure chamber and the second output air flow path is connected to the second pressure chamber. In the second rotational position, the first output air flow path is connected to the second pressure chamber and the second output air flow path is connected to the first pressure chamber.

2. The air chuck according to claim 1, characterized in that, The valve unit includes: a separate supply port (66), a first exhaust port (84) with a variable throttle valve, and a second exhaust port (86) with a variable throttle valve. The supply port is connected to the first solenoid valve and the second solenoid valve via a predetermined flow path. The first exhaust port is connected to the first solenoid valve via a predetermined flow path, and the second exhaust port is connected to the second solenoid valve via a predetermined flow path.

3. The air chuck according to claim 1, characterized in that, The valve unit includes a valve unit body (62) having a cylindrical outer wall portion (64), and the chuck unit includes a disc-shaped connector body (36) connected to the valve unit body.

4. The air chuck according to claim 3, characterized in that, The first solenoid valve and the second solenoid valve are assembled on the valve unit body, and the outer wall of the valve unit body has an opening (64a) so that the first solenoid valve and the second solenoid valve can be installed and removed.

5. The air chuck according to claim 4, characterized in that, A cylindrical waterproof cover (98) covering the opening is installed on the valve unit body.

6. The air chuck according to claim 3, characterized in that, The chuck unit has a magnetic sensor (34) for detecting the position of the piston, and the outer wall of the valve unit body has an electrical connector (68) for connecting the lead (34a) of the magnetic sensor, the lead (58d) of the first solenoid valve and the lead (60d) of the second solenoid valve.

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