JP4123458B2 - Gripper - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gripper for gripping an article, and more particularly to an improvement of a gripper including an elastic body that expands and contracts by a pressure fluid supplied and discharged.
[0002]
[Prior art]
Conventionally provided with an elastic body that is provided in a housing and forms an insertion portion into which an article is inserted, and a pressure fluid supply and discharge means that supplies and discharges pressure fluid to and from the elastic body to expand and contract the inner diameter of the insertion portion Is known (Japanese Patent Laid-Open No. 7-96913).
In this type of gripper, an article is inserted into an enlarged insertion portion, and in that state, the inner diameter of the insertion portion is contracted to grip the article.
[0003]
[Problems to be solved by the invention]
However, with the above gripper, when the article length is the same and the thickness is slightly different, the gripper can be gripped with almost no problem, and the insertion amount of the article exceeds the effective insertion length of the insertion portion. However, if the amount of insertion is less than the effective insertion length of the insertion part, even if the thickness is almost the same, there will be an excess part that is grabbed empty. There is a problem that it cannot be used because it occurs. That is, since the surplus portion repeats expansion more than usual, there is a problem that the progress of deterioration of the elastic body is accelerated and the durability is impaired, and in some cases, the article is pushed back to reduce the insertion amount.
In view of the above-described circumstances, the present invention provides a gripper capable of ensuring durability while improving the dual-use property as compared with the related art.
[0004]
[Means for Solving the Problems]
That is, according to the first aspect of the present invention, an elastic body that is provided in the housing and forms an insertion portion into which an article is inserted, and a pressure fluid supply and discharge device that expands and contracts the inner diameter of the insertion portion by supplying and discharging pressure fluid into the elastic body. Means for gripping the article by contracting the inner diameter of the insertion part with the article inserted into the insertion part,
To the housing, and deeply inserted forward position in the insertion portion, it provided an expansion preventing member which is moved back and forth in a retracted position out of the shallow inserted or insertion portion in the insertion inside join the club, the expansion inhibiting member is normally Is positioned at the forward position by the urging means, and when the article is inserted into the insertion portion, it is brought into contact with the article and moved to the retracted position, and the expansion preventing member is inserted in the insertion portion. The insertion part of the other part is prevented from contracting freely and the insertion part of the other part is contracted .
According to the first aspect of the invention described above, when the amount of articles inserted is shorter than the effective insertion length of the insertion portion, the expansion preventing member can prevent expansion of the surplus portion of the elastic body. Furthermore, by setting the expansion preventing member so that it can be retracted to the retracted position removed from the insertion portion of the elastic body, even an article longer than the effective insertion length of the insertion portion can be gripped.
Therefore, even if the effective insertion length of the insertion portion of the elastic body is set to be long to improve the combined use, the expansion preventing member prevents the excess portion from being grabbed, so that the durability is not impaired, and the excess It is possible to prevent the article from being pushed back by the portion .
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to the illustrated embodiment. In FIG. 1, reference numeral 2 denotes a caser provided with the gripper 1 of the present invention, and this caser 2 is conveyed on one belt conveyor 3 arranged at a predetermined interval. A container 4 (article) is held and accommodated in a case 6 that is conveyed on the other belt conveyor 5.
The caser 2 is supported by a frame 10 fixed to the floor so as to be swingable and extends upward, and an upper arm 12 attached to the upper end of the lower arm 11 so as to be swingable and extending leftward in the drawing. And a hollow cylindrical member 13 that extends downward from the tip of the upper arm 12 and has the gripper 1 attached to the lower end thereof. Since the caser 2 composed of the lower arm 11 and the upper arm 12 is conventionally known, detailed description thereof is omitted here.
[0006]
As shown in FIG. 2, the gripper 1 has a housing 15 attached to the tubular member 13 with its opening facing downward, and is press-fitted into the housing 15 with its opening facing downward. A cup-shaped inner member 16 constituting a part of the housing 15, an annular first elastic body 17 disposed below the inner member 16 and intersecting the insertion direction of the container 4 indicated by an arrow, An annular second elastic body 18 that is disposed below the first elastic body 17 and intersects the insertion direction of the container 4, and provided in the inner member 16, and in the insertion portion 17 ′ of the first elastic body 17. And an expansion preventing member 19 to be inserted.
[0007]
The first elastic body 17 can hold a pressure fluid between the cylindrical first collar 25 press-fitted in the housing 15. In other words, the first elastic body 17 is formed in a thick shape and is annularly connected to the upper bead portion 17A with an annular upper bead portion 17A that is sandwiched between the first collar 25 and the inner member 16 while maintaining airtightness. A thin cylindrical expansion / contraction portion 17B that is provided and extends downward, and a thick wall that is connected to the expansion / contraction portion 17B and is airtightly sandwiched between the first collar 25 and the plate ring 26. In addition, the first elastic body 17 is in contact with the first collar 25 in the contracted state where no pressure fluid is supplied. And the inside of this 1st elastic body 17 is made into insertion part 17 'in which the container 4 is inserted.
On the other hand, the second elastic body 18 can hold the pressure fluid between the cylindrical second collar 27 press-fitted in the housing 15. That is, the second elastic body 18 is formed thick and has an annular upper bead portion 18A that is sandwiched between the second collar 27 and the plate ring 26 while maintaining airtightness, and is connected to the upper bead portion 18A. A thin cylindrical expansion / contraction portion 18B that extends downward and is connected to the expansion / contraction portion 18B, and the second collar 27 and a ring-shaped screw 45 screwed into the housing 15 are hermetically sealed. The second elastic body 18 is in contact with the second collar 27 in the contracted state shown in the figure when no pressure fluid is supplied. And the inside of this 2nd elastic body 18 is made into insertion part 18 'in which the container 4 is inserted.
The ring screw 45 presses the inner member 16, the first elastic body 17 and the first collar 25, the ring plate 26, the second elastic body 18 and the second collar 27 between the housing 15 and the housing 15. While maintaining airtightness between members, the lower part of the inner surface, which is enlarged in a tapered shape, is brought into contact with the shoulder of the container to prevent the container from shaking.
[0008]
The inner member 16 constitutes an upstream portion of the flow path 30 for supplying and discharging the pressure fluid to and from the space between the first elastic body 17 and the second elastic body 18 between the housing 15 and FIG. 3, a cruciform slit 22 formed on the upper surface of the upper portion 16A of the inner member 16 and forming a cruciform radial space 22 ′ between the lower surface of the upper portion 15A of the housing 15, A circumferential chamfer 23 is formed by chamfering the corners of the upper surface 16A of the inner member 16 over the entire circumference and forming an annular space 23 ′ communicating with the lower surface of the upper portion 15A of the housing 15 in communication with the radial space 22 ′. Further, four circumferentially equidistant positions on the outer surface of the cylindrical portion 16B of the inner member 16 are chamfered in the axial direction, and the annular space 23 'is formed between the inner surface of the cylindrical portion 15B of the housing 15. 4 communicating And an axial chamfer 24 that forms an axial space 24 ′. The radial space 22 ′, the annular space 23 ′, and the axial space 24 ′ that communicate with each other constitute an upstream portion of the flow path 30. is doing. The central portion of the radial space 22 ′ is connected to a not-shown on-off valve (pressure fluid supply / discharge) via a passage 43 in the joint 33 embedded in the upper portion 15 A of the housing 15 and a passage 44 in the cylindrical member 13. Means). The on-off valve selectively connects the passage 44 to a pressure fluid supply source or the atmosphere.
Further, the cylindrical first collar 25 forms an intermediate portion of the flow path 30 with the housing 15, and as shown in FIGS. 2 and 4, an annular flange portion 25 </ b> A that is pressed into the housing 15. The axial chamfered portion 28 is formed at four circumferentially equidistant positions on the outer peripheral surface of the outer peripheral surface and forms an axial space 28 'extending in the axial direction between the inner surface of the cylindrical portion 15B of the housing 15; A small diameter portion 25B connected to the lower end of the annular flange portion 25A and forming an annular space 25B 'communicating with the four axial spaces 28' between the inner surface of the cylindrical portion 15B of the housing 15; A through-hole 29 is formed at equal circumferential circumferential positions of the small-diameter portion 25B and penetrates the small-diameter portion 25B and communicates with the space between the annular space 25B ′, the first elastic body 17, and the first collar 25. And these phases Axial space 28 'communicating with the, and forms a part of the flow path 30 exits the annular space 25B' and the through hole 29. The axial space 28 'and the axial space 24' are communicated with each other by an annular groove 15C in which the inner surface of the cylindrical portion 15B of the housing 15 is cut out in the circumferential direction. Thus, part of the flow path 30 is configured.
Next, the cylindrical second collar 27 constitutes a downstream portion of the flow path 30 with the housing 15, and press-contacts while keeping hermeticity inside the housing 15 as shown in FIGS. 2 and 5. A small-diameter portion 27B that is connected to the upper end of the annular flange portion 27A and forms an annular space 27B ′ is provided between the inner surface of the cylindrical portion 15B of the housing 15 and the flow path 30 is formed by the annular flange portion 27A. It is closed. The annular space 27 </ b> B ′ and the annular space 25 </ b> B ′ are communicated with each other by a plurality of notches 26 </ b> A in which circumferential positions at equal intervals in the outer peripheral portion of the plate ring 26 are notched.
Thus, when the pressure fluid supply source and the passage 44 and the passage 33 are communicated with each other by the opening / closing valve, the pressure fluid is supplied to the annular space between the first elastic body 17 and the first collar 25 via the flow path 30. On the other hand, since the pressure fluid is supplied to the space between the second elastic body 18 and the second collar 27, the first elastic body 17 and the second elastic body 18 expand simultaneously and the insertion portions 17 ′, 18 ′. And the diameter is reduced (not shown).
[0009]
Next, the expansion preventing member 19 will be described. The expansion preventing member 19 is formed in a substantially cup shape, and has a smaller diameter than the insertion portion 17 ′ of the first elastic body 17 when contracted and a larger diameter than the insertion portion 17 ′ of the first elastic body 17 when expanded. A bottomed cylindrical cup portion 19A formed on the upper end of the cup portion 19A, and a slidable contact portion 19B having an arcuate cross section that swells radially outward and slidably contacts the inner surface of the inner member 16; It has.
And in the cup part 19A with the opening side facing upward, the lower end part of the spring 46 ( biasing means ) connected to the convex part 16C formed on the lower surface of the upper part 16A of the inner member 16 is press-fitted, The spring 46 allows the expansion prevention member 19 to move forward and backward in the same direction as the insertion direction of the container 4. Further, a vent hole 47 is provided on the outer peripheral surface of the cup portion 19A so as to communicate the space formed between the expansion preventing member 19 and the inner member 16 to the outside. Can smoothly move forward and backward with respect to the inner member 19.
An annular stopper ring 48 protruding radially inward is fitted in an annular groove 16D formed at a position below the inner peripheral surface of the inner member 16, and is urged downward by a spring 46. The expansion preventing member 19 is normally held at an advanced position where the flange portion 19 </ b> A is in contact with the stopper ring 48. In this forward movement position, the tip of the cup portion 19A is located below the axial intermediate portion of the first elastic body 17, and thereby the axial intermediate portion that bulges most radially inward during expansion. Can be prevented from expanding.
[0010]
According to the gripper 1 having the above-described configuration, when the neck portion 4B of the container 4 is long and the insertion amount to be inserted into the gripper 1 is large, specifically, the neck portion 4B exceeds the insertion portion 18 'of the second elastic body 18. When the insertion part 17 ′ of the first elastic body 17 can be inserted, the cap 50 (sealed) is used to seal the container 4 to the expansion preventing member 19 inserted deeply into the insertion part 17 ′. If not, the mouth of the container will come into contact.
As a result, the expansion preventing member 19 in contact with the cap 50 is raised (retracted) relative to the housing 15 and the first elastic body 17 while compressing the spring 46 from the illustrated forward position as the gripper 1 is lowered. The retraction is stopped when the lowering of the gripper 1 is stopped.
When the lowering of the gripper 1 is stopped, the pressure fluid is supplied to the flow path 30 by the on-off valve (pressure fluid switching means), whereby the expansion / contraction portion 17B of the first elastic body 17 and the second elasticity are supplied. The expansion / contraction part 18B of the body 18 expands and the respective insertion parts 17 'and 18' contract.
At this time, if the cap 50 of the container 4 does not exceed the upper end of the first elastic body 17, specifically, the first elastic body has an insertion amount of the container equal to or greater than the effective insertion length of the insertion portion 18 ′ of the second elastic body 18. When the length is equal to or shorter than the effective insertion length of the 17 insertion portions 17 ′, the first elastic body 17 presses and holds the expansion preventing member 19 and the cap 50, and the second elastic body presses and holds the neck portion 4 </ b> B. Thereby, even if the insertion amount is a container which is not less than the effective insertion length of the second elastic body 18 and not more than the effective insertion length of the first elastic body 17, it is possible to prevent partial empty gripping of the first elastic body 17 and 4 can be gripped satisfactorily.
On the other hand, when the upper end of the cap 50 exceeds the upper end of the first elastic body 17, specifically, when the insertion amount of the container exceeds the total effective insertion length of the second elastic body 18 and the first elastic body 17, Since the expansion preventing member 19 can be raised and retracted to a position where it is not pressed by the first elastic body 17 as indicated by a two-dot chain line, the first elastic body 17 holds the cap 50 and the neck portion 4B. On the other hand, the second elastic body 18 also presses and holds the neck portion 4A. Thereby, even if it is a container whose insertion amount exceeds the total effective insertion length of the 1st elastic body 17 and the 2nd elastic body 18, it can hold | grip favorably.
In the case of the container 4 having a short neck portion 4B and a small insertion amount inserted into the gripper, specifically, the neck portion 4B is inserted up to the insertion portion 18 ′ of the second elastic body 18, but the first elastic body 17 When the insertion portion 17 ′ is not inserted, the expansion preventing member 19 is not separated from the stopper ring 48. Thereby, the first elastic body 17 presses and holds the expansion preventing member 19 inserted deeply into the insertion portion 17 ′, and the second elastic body 18 presses and holds the cap 50. Thereby, even if it is a container below the insertion amount of the 1st elastic body 17, the empty grasping of the 1st elastic body 17 can be prevented and the container 4 can be favorably gripped only by the 2nd elastic body 18. .
Therefore, as understood from the above description, the first elastic body 17 and the second elastic body 18 are provided side by side in the insertion direction and the total effective insertion length is set to be large, so that the duality can be improved. In some cases, an excess portion for empty-grabbing the container is generated in some cases. However, since the empty portion is blocked by the expansion preventing member 19, the durability of the first elastic body 17 is not impaired. .
The portion of the container that is held by the first elastic body 17 and the second elastic body 18 is not limited to the above description, but depends on conditions such as the axial dimension of the cap and the insertion amount of the neck of the container. Is different.
[0011]
Next, FIG. 6 shows a second embodiment of the present invention. In the first embodiment, the first elastic body 17 and the second elastic body 18 are provided side by side so as to intersect with the insertion direction of the container 4, and the effective insertion length is set to be long. The body is omitted and the effective insertion length of the elastic body 118 corresponding to the second elastic body is set to be single and long.
Then, as the length of the expansion / contraction part 118B of the elastic body 118 is increased, as shown in FIG. 7, a small diameter part 127B of the collar 127 corresponding to the second collar 27 of the first embodiment is formed longer in the axial direction. In addition, the through-hole 141 that penetrates the small-diameter portion 127B has two upper and lower stages. An annular space 127B ′ formed by the cylindrical portion 127B and the cylindrical portion 115B of the housing 115 is replaced with four axial spaces 124 ′ via an annular groove 115C formed in the cylindrical portion 115B of the housing 115. Communicating with
By the way, in the said 1st Example, the expansion | extension prevention member 19 was located in the forward position, but the front-end | tip was located below the axial direction intermediate part of the 1st elastic body 17, However, This Example Then, in the state where the expansion preventing member 119 is located at the forward movement position, the tip thereof is located slightly above the middle of the effective insertion length of the elastic body 118. That is, the axially intermediate portion of the elastic body 118 is the portion that expands most radially inward, and the container is always inserted up to the axially intermediate portion. This is set to be less than half of the effective insertion length.
The rest of the configuration is the same as that of the first embodiment, and the same members as those of the first embodiment are numbered by adding “100” to the reference numerals used in the first embodiment.
[0012]
According to the gripper 101 having the above-described configuration, when the neck of the container is long and the insertion amount to be inserted into the gripper 101 is large, specifically, the cap attached to the container is inserted to a position where it abuts against the expansion preventing member 119. In the case where it is possible to do so, the expansion preventing member 119 abutting against the cap rises relative to the housing 115 and the elastic body 118 while compressing the spring 146 from the illustrated forward position as the gripper 101 descends. The retraction is stopped when the lowering of the gripper 101 is stopped.
When the lowering of the gripper 101 is stopped, the pressure fluid is supplied to the flow path 130 by the on-off valve (pressure fluid switching means), whereby the expansion / contraction part 118B of the elastic body 118 is expanded and inserted. The portion 118 'contracts.
At this time, if the cap does not exceed the upper end of the elastic body 118, specifically, if the amount of insertion is less than or equal to the effective insertion length of the insertion portion 118 ′ of the elastic body 118, the elastic body 118 is not limited to the expansion preventing member 119. Press and hold the neck of the cap or container. Thereby, even if the insertion amount is a container having an insertion length equal to or smaller than the effective insertion length of the elastic body 118, the container can be gripped by preventing the empty portion of the elastic body 118 from being gripped by an empty portion. The surplus portion may be pushed back in some cases, but such push back can be prevented.
On the other hand, when the upper end of the cap exceeds the upper end of the elastic body 118, specifically, when the insertion amount of the container exceeds the effective insertion length of the elastic body 118, the expansion preventing member 119 is indicated by a two-dot chain line. Therefore, the elastic body 118 grips the cap and the neck.
Therefore, as can be understood from the above description, it is possible to improve the combined use by setting the effective insertion length of the single elastic body 118 to be large, and in some cases, an extra portion for holding the container empty in some cases However, since the unoccupied portion of the surplus portion is blocked by the expansion preventing member 119, the durability is impaired, or the pushing back of the container by the surplus portion can be prevented.
The portion of the container that is held by the elastic body 118 is not limited to the above description, and varies depending on conditions such as the axial dimension of the cap and the insertion amount of the neck of the container .
[0013]
In the first embodiment, only two elastic bodies , the first elastic body 17 and the second elastic body 18 , are provided. However, the present invention is not limited to this, and a larger number of elastic bodies are arranged. May be.
[0014]
Moreover, in the said 1st Example and 2nd Example, although the expansion | extension prevention members 19 and 119 were comprised so that it could retract to the position which does not contact with the elastic bodies 17 and 118, it is not limited to this.
[0015]
Furthermore, in the said 1st Example and 2nd Example , although each elastic body is continuously formed in cyclic | annular form, it is not limited to this, You may be discontinuous.
[0016]
Furthermore, in the first embodiment and the second embodiment , the flow path for supplying and discharging the pressure fluid is formed in the housing. In particular, when there are three or more elastic bodies, this is easier to configure.
[0017]
【The invention's effect】
As described above, according to the present invention, it is possible to prevent the durability of the elastic body from being impaired even if the effective insertion length of the elastic body is set longer than that in the past to improve the combined use. An effect is obtained.
[Brief description of the drawings]
FIG. 1 is a side view of a caser 2 showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the gripper 1;
3 is a perspective view showing an inner member 16. FIG.
4 is a perspective view showing a first collar 25. FIG.
5 is a perspective view showing a second collar 27. FIG.
FIG. 6 is a cross-sectional view of a gripper 101 showing a second embodiment.
7 is a perspective view showing a collar 127. FIG.
[Explanation of symbols]
1, 101 ... gripper 4 ... container (article)
15, 115 ... housing 17 ... first elastic body
18 ... second elastic member 118 ... elastic body 17 ', 18', 118 '... insertion portion 19, 119 ... expandable blocking member

Claims (3)

An elastic body that is provided in the housing and forms an insertion portion into which an article is inserted; In a gripper that grips the article by shrinking the inner diameter of the insertion portion with the article inserted into the
To the housing, and deeply inserted forward position in the insertion portion, it provided an expansion preventing member which is moved back and forth in a retracted position out of the shallow inserted or insertion portion in the insertion inside join the club, the expansion inhibiting member is normally Is positioned at the forward position by the urging means, and when the article is inserted into the insertion portion, it is brought into contact with the article and moved to the retracted position, and the expansion preventing member is inserted in the insertion portion. A gripper that prevents free contraction of an insertion portion in the portion and contracts the insertion portion in another portion. The gripper according to claim 1 , wherein a plurality of the elastic bodies are provided in the insertion direction of the article. The plurality of elastic bodies are composed of a first elastic body and a second elastic body so that the article can be inserted into the insertion portion of the first elastic body via the insertion portion of the second elastic body, and each elasticity The pressure fluid can be supplied to and discharged from the pressure fluid supply / discharge means to the body,
  Further, the advance position is set to a position deeply inserted into the insertion portion of the first elastic body, the retracted position is set to a position away from the insertion portion of the first elastic body, and the expansion preventing member is positioned at the retracted position. In the state, the article is gripped by the insertion part of the first elastic body and the insertion part of the second elastic body, and the article is gripped by the insertion part of the second elastic body in a state where the expansion preventing member is positioned at the advanced position. The gripper according to claim 2, characterized in that:

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