JP2000310383A - Pipe coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To limit the movement in the direction of inserting and pulling out a pipe so as to improve salability in an easily manufactured constitution by disposing a claw body having a claw part projected to inhibit a pipe from being pulled out slidably in the direction of intersecting the direction of inserting and pulling out the pipe in plural opening parts of the coupling main body side wall. SOLUTION: A coupling main body 10 has opening parts 14 opened in plural portions of a cylindrical peripheral wall 12 in which a pipe 42 can be inserted. The opening part 14 has a claw body 20 slid in the direction intersecting the direction of inserting and pulling out the pipe 42 and is disposed with the outer surface 25 exposed outwardly. The claw body 20 has a claw part 24 projected on the inside facing to the interior of the coupling main body 10 to eat into the outer wall of the pipe 42, thereby inhibiting pull-out of the pipe. Further, in the coupling main body 10, a lock sleeve 30 having a reduced diameter inner peripheral part 32 in the midway part in the direction of inserting and pulling out the pipe 42 is externally fitted to be movable in the direction of inserting and pulling out the pipe 42. Thus, the lock sleeve 30 is slid to make the claw part 24 of the claw body 20 eat into the outer wall of the pipe 42.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint.

[0002]

2. Description of the Related Art There are various types of pipe joints for connecting pipes for flowing a fluid. For example, a pipe joint as shown in FIG. 3 has been proposed, and has the following configuration. Reference numeral 80 denotes a joint body, and a distal end side of a collet ring 82 is fitted into a connection port of the pipe 42 of the joint body 80 so as to be movable in the axial direction. The collet ring 82 has a basically cylindrical shape into which the pipe 42 can be inserted, and a portion corresponding to the inner side of the connection port is divided into a plurality in the circumferential direction and has a claw portion 84 on an inner surface. A stop 86 is provided. The collet ring 82 is guided by the inner wall guide portion of the joint body 80 by being pulled in the exit direction of the connection port, and the tip end of each locking piece 86 moves inward and narrows, and the claw portion 8
An inclined surface 88 which is inclined to expand toward the inside of the connection port on the outside of the locking piece 86 so that the outer wall 4 of the pipe enters the outer wall of the pipe.
Are formed. Further, a through hole 90 extending in the axial direction is formed in the joint body 80 corresponding to the distal end of the locking piece 86. Each of the locking pieces 86 protrudes into the through-hole 90, and when the collet ring 82 is pushed to release the biting of the claw portion 84 into the pipe and pull out the pipe, the corresponding joint body 80 Of the locking piece 8
A protrusion 94 is formed to extend the outer surface 6.

Reference numeral 96 denotes a locking step, and a locking piece 86 is provided.
When the collet ring 82 moves rearward, the collet ring 82 abuts on the inner wall 90a of the through hole 90 to restrict the movement of the collet ring 82. Thereby, the collet ring 82 can be prevented from coming out of the joint body 80. A thread 98 for screwing the pipe joint to a pressure device (not shown) or the like is provided on the left end side of the joint main body 80. Reference numeral 99 denotes an elastic ring, which is formed in a ring shape using a rubber material, and is in close contact with the outer wall of the inserted pipe and the inner surface of the joint body to prevent leakage of fluid.

According to the above-mentioned conventional pipe joint, after the pipe 42 is inserted into the joint body 80, the pipe 42 moves in a slightly withdrawing direction together with the collet ring 82, so that the claw portion 84 of the collet ring causes the pipe 42 to move. Pipe 42
Can be prevented from getting out. The collet ring 8
The movement of the second elastic member 99 in the direction of exiting from the inside of the joint body 80 is such that when the inner side of the pipe joint has a high pressure, the elastic ring 99 which moves in the direction of exiting from the inside of the joint body 80 by the action of the high pressure causes the collet ring 82 to move. It can also be done by pressing. Further, by pushing the collet ring 82, the locking piece 86 is opened and the engagement of the claw portion 84 into the tube 42 is released, so that the tube 42 can be extracted.

[0005]

However, in the conventional pipe joint as described above, the pipe 42 moves in the direction in which the pipe 42 is slightly pulled out together with the collet ring 82, so that the claw portion 84 fits into the outer wall of the pipe 42 so that the pipe 42 does not move. Is prevented from coming off, and allows the tube 42 to move (swing) in the insertion / removal direction. Therefore, the pipe 42 is easily oscillated in the axial direction (pull-out direction) due to the pulsation due to the change in the air pressure. At this time, the sealing performance (airtightness) is slightly increased.
However, there is a problem in that the data is easily lost.

The rearward movement of the collet ring 82 is restricted by the contact of the locking step 96 with the inner wall 90a of the through hole 90. However, since the collet ring 82 does not restrict the distal end of the locking piece 86 at all. In addition, the claw portion 84 may be further caught in the outer wall of the tube 42, and the tube 42 may be greatly deformed. Such a large deformation of the pipe 42 causes a problem of deteriorating the sealing performance of the connection of the pipe 42 and a problem of increasing a resistance applied to a fluid flowing in the pipe. If the claw portion 84 is inserted into the pipe 42 more than necessary and the insertion portion of the collet ring 82 inserted into the joint body 80 is too small in diameter, the collet ring 82 and the pipe 42 are integrated. There is also a problem of getting out.

Furthermore, in the conventional pipe joint, the shapes of the collet ring 82 and the joint body 80 are complicated. Therefore, when manufacturing this pipe joint, when molding with plastic (resin), a mold having a complicated shape is required,
It was difficult to manufacture the mold. Also, due to the limited space, it was difficult to form the protrusion 94 from a resin material into a shape having sufficient strength. Therefore, there is a problem that it is difficult to form all parts with a resin material. In addition, since the conventional pipe joint has a complicated shape, it is of course difficult to manufacture it with metal.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a pipe joint which has a structure which is easy to manufacture and which can restrict the movement of the pipe in the insertion / removal direction to improve the sealing property.

[0009]

To solve the above-mentioned problems, the present invention has the following arrangement. That is, the present invention provides a joint body having a tubular side peripheral wall into which a pipe can be inserted, and having a plurality of openings provided at a plurality of locations of the side peripheral wall, and corresponding to the opening of the joint body. Each is provided,
The opening is slidably disposed in a direction intersecting with the pipe insertion / removal direction in the joint body, and is disposed such that an outer surface is exposed outward from the opening, and faces the inside of the joint body. Inside, a plurality of claw bodies projectingly provided with claw portions that bite into the outer wall of the inserted tube to prevent the tube from being pulled out, are externally fitted to the joint body, and are disposed so as to be movable in the direction of pulling and inserting the tube. Has a reduced diameter inner peripheral portion provided with an inner diameter reduced in a middle part of the pipe insertion / removal direction, and when moved in one direction of the pipe insertion / removal direction, the reduced diameter inner peripheral portion is A lock sleeve that abuts against the outer surface of the claw body and presses and slides the claw body inward, whereby the claw portion bites into the outer wall of the pipe, and constantly urges the claw body outward of the joint body; The lock sleeve moves in the other direction of the tube insertion / removal direction. When the reduced diameter inner peripheral portion does not abut against the outer surface of the claw body by being moved, the claw body is slid outward of the joint body to release the claw portion from biting into the outer wall of the pipe. A biasing means, and a ring-shaped seal member which is fitted inside the joint body behind the claw body and seals between an inner peripheral surface of the joint body and an outer peripheral surface of a pipe to be inserted. Have.

In addition, since the claws are slid in the direction perpendicular to the direction in which the tubes are inserted and withdrawn in the joint body, the claws can be slidably moved reciprocally, and the tube can be prevented from swinging. Can be suitably maintained.

Further, since the urging means is formed integrally with the claw body in the form of a leaf spring, the number of parts can be reduced, and the number of parts can be reduced, so that the structure can be easily assembled. It can be manufactured at low cost.

In addition, since the biasing means is an elastic member provided separately from the claw body, it can suitably cope with an application requiring durability and an application for connecting a large-diameter pipe. Connection reliability can be improved.

[0013] Further, at the end of the joint body opposite to the portion connected to the pipe by the claw body, the diameter is increased to form a step so that it can be connected to another communication path. Portion, and the enlarged diameter step portion is provided with a locking portion formed with a slit so as to be able to reduce the diameter. Since the stepped portion is formed so as to be able to be sealed via the and the ring-shaped seal member, the pipe joint itself can be easily and suitably connected to another communication path with a simple shape.

[0014]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view taken along an axis to show one embodiment of a pipe joint according to the present invention. The left half of the center line in FIG. 1 shows a state in which the claws are slid so that the claws bit into the outer wall of the inserted tube. The right half of the center line in FIG. A state is shown in which the claws are slid so that the bites of the claws into the outer wall are released. Also,
FIG. 2 is a cross-sectional view of the embodiment of FIG. 1 cut in a direction perpendicular to the axis to show a form of a claw body.

Reference numeral 10 denotes a joint body, which has a cylindrical side wall 12 into which a pipe 42 can be inserted, and has a plurality of openings 14 provided at a plurality of positions on the side wall 12. In the present embodiment, a later-described claw body 20 of the joint body 10 is used.
Cylindrical side wall 1 which is a portion connected to pipe 42 by
A locking portion 16 is provided at the tip end opposite to 2 so that it can be connected to another communication path with one touch. The locking portion 16 has an enlarged diameter stepped portion 16 a that is enlarged in diameter to form a stepped portion.
Are formed, and a slit 16b is formed so that the diameter increasing step 16a can be reduced in diameter. Reference numeral 18 denotes a stepped portion. The other communication path and a ring-shaped sealing member (for example, an 'O'-ring) 38) so as to be airtight (sealable). Thus, the pipe joint itself can be easily and suitably connected to another communication path with a simple shape.

Reference numeral 20 denotes a claw body, which is provided corresponding to the opening 14 of the joint body 10, and is slidably disposed in the opening 14 in a direction intersecting with the insertion and removal direction of the pipe 42 in the joint body 10. And the opening 14
The outer surface 25 is disposed so as to be exposed to the outside. In addition, the sliding direction of the claw body 20 of the present embodiment is a direction orthogonal to the insertion / removal direction of the pipe 42 in the joint body 10. As a result, the claw body 20 can be suitably slid back and forth and locked to the tube 42, and the movement in the insertion / removal direction is regulated by the inner wall of the opening 14, so that the tube 42 is prevented from swinging, 42 can be suitably held by a pipe joint. The claw body 20 has a claw portion 24 protruding from the inside facing the inside of the joint body 10 so as to bite into the outer wall of the inserted tube 42 to prevent the tube from being pulled out. The claw portion 24 is formed with a sharp tip so as to bite (lock) into the outer wall of the tube 42, and is locked with a line following the outer wall shape of the tube 42 as shown in FIG. It is formed in an arc shape as possible.

In this embodiment, the corner of one end of the outer surface 25 of the claw body 20 is a curved surface 21. This curved surface 21 is formed by a reduced-diameter inner peripheral portion 32 of a lock sleeve 30 described later.
Is guided so that the inner wall surface can appropriately contact the outer side surface 25. The corner at one end of the outer surface 25 is not limited to the curved surface 21, but may be formed in a tapered surface shape whose diameter decreases toward the corner at one end. It can be guided appropriately.

Reference numeral 30 denotes a lock sleeve, which is a joint body 1
0, and is provided so as to be movable in the insertion / removal direction of the tube 42, and has a reduced diameter inner peripheral portion 32 provided with a reduced inner diameter at a middle portion in the insertion / removal direction of the tube 42. When the lock sleeve 30 is slid (moved) in one direction of insertion / removal of the tube 42 (insertion direction in the present embodiment), the reduced-diameter inner peripheral portion 32 comes into contact with the outer surface 25 of the claw body 20. To slide the claw body 20 inward. As a result, the claws 24 can be cut into the outer surface (outer wall) of the tube 42. Also, this lock sleeve 30 is
The other of the insertion / removal directions 2 (pull-out direction in this embodiment)
When moved to the position, the reduced-diameter inner peripheral portion 32 is positioned so as not to press the claw body 20, whereby the pipe 4 of the claw portion 24 is moved.
2 can be released from biting into the outer wall.

In this embodiment, the lock sleeve 3
An inner tapered portion 35 is formed at one end, which is the inner end of the inner diameter reduced diameter portion 32 into which the tube 42 is inserted, so as to increase in diameter toward the end.
When the lock sleeve 30 is moved in the insertion direction by the inner surface tapered portion 35, the curved surface 21 provided at the corner of one end of the claw body 20 can be suitably pressed with a wide slope. As described above, the claw body 20 can be appropriately pressed by the lock mechanism including the lock sleeve 30, so that the claw portion 2
4 can be reliably cut into the outer wall of the tube 42, and the tube 42 can be properly and reliably prevented from coming off. The one end of the reduced diameter inner peripheral portion 32 is not limited to the tapered shape as in the present embodiment, and the same effect can be obtained even if it is formed in a curved shape.

In this embodiment, the lock sleeve 30
The inner peripheral portion 31 at one end and the inner peripheral portion 33 at the other end are formed to be larger in diameter than the reduced inner peripheral portion 32 in the middle. The inner peripheral portion 31 at one end and the inner peripheral portion 33 at the other end have a constant inner diameter at least in a predetermined section. Since the lock sleeve 30 is formed in this manner, the lock sleeve 30 can be slid in the direction in which the tube 42 is inserted and withdrawn. In addition, the portion of the reduced diameter inner peripheral portion 32 of the present embodiment where the inner diameter is set to be smallest is not continuous with the entire inner circumference as shown in FIG.
It is shaped to fit into the opening 13a of the outer sleeve portion described later. That is, the lock sleeve 30 is externally fitted (attached) to the joint body 10 so as not to be easily detached by press fitting.

Reference numeral 50 denotes a spring portion, as shown in FIG.
When the claw body 20 is constantly urged to the outside of the joint body 10 and the lock sleeve 30 is moved in the other direction of the insertion / removal direction of the pipe 42 so that the reduced-diameter inner peripheral portion 32 does not contact the outer surface of the claw body 20. Is an example of an urging means for sliding the claw body 20 to the outside of the joint body 10 to release the claw portion 20 from biting into the outer wall of the tube 42. The urging means (spring portion 5) of this embodiment
0) are integrally formed on both sides of the claw body 20 in a leaf spring shape. By providing the pair of spring portions 50 in this manner, the claws 20 can be urged to the outside of the joint body 10 in a well-balanced manner. The spring portion 50 is formed in an ear plate shape on the outer peripheral side of the claw body 20, and is provided in a curved shape so that the inner side becomes a convex surface. For this reason, the spring 5
0 is appropriately stored in the concave portion 19 formed on the outer peripheral wall surface of the joint main body 10, and the claw body 20 can be suitably positioned with respect to the joint main body 10. Since the spring portion 50 is formed integrally with the claw body 20 in a leaf spring shape, the number of components is reduced, and the number of components is small, so that the configuration can be made easy to assemble. it can.

The urging means according to the present invention is not limited to the spring portion 50 described above, but may be an elastic member provided separately from the claw body 20. As the elastic member, for example, a coil spring or a leaf spring can be used. By providing the elastic member separately as described above, it is possible to suitably cope with an application requiring durability and an application of connecting a large-diameter pipe, and improve the reliability of the connection.

By providing the urging means such as the spring portion 50 as described above, the claw body 20 is always urged outward from the joint body 10, so that the claw body 20 is moved inward of the joint body 10. Is regulated. In the present embodiment, the claw body 20 is not moved inward than the claw body 20 is pressed and slid inward by the reduced-diameter inner peripheral portion 32 of the lock sleeve 30.
The urging force of the spring part 50 acts. Therefore, it is possible to prevent the passage of the tube 42 from being reduced by tightening the tube 42 more than necessary.

Reference numeral 40 denotes a ring-shaped sealing member, for example, an 'O'-ring may be used as in this embodiment.
This ring-shaped sealing member 40 is fitted inside the joint body 10 at a position farther than the position where the claw body 20 is arranged, and is provided between the inner peripheral surface of the joint body 10 and the outer peripheral surface of the pipe 42 to be inserted. Seal. A step 17 is formed in the joint main body 10 in a stepped manner so that the ring-shaped seal member 40 is suitably located. The ring-shaped sealing member 40
Is not limited to the 'O'-ring as in the present embodiment, but is formed of an elastic material such as synthetic rubber, and is fitted in the joint body 10 to be fitted inside the joint body 10 and the outer circumferential surface of the pipe 42. Any material may be used as long as it seals the space between them.

Next, a specific configuration of the joint body 10 according to the present embodiment will be described. Reference numeral 58 denotes an inner sleeve, which is formed in a tubular shape and has the opening 1 on its side peripheral wall.
4 is formed and fitted (inner-fitted) inside the outer sleeve portion 13 which is formed in a tubular shape so as to form the outer peripheral portion of the joint body 10, and is integrally formed with the tubular shape of the joint body 10. Side peripheral wall 12 is formed. In the present embodiment, the male step 58a provided on the rear end side of the inner sleeve 58 is press-fitted into the female step 13b formed by forming the opening 13a in the outer sleeve 13. It is fixed by fitting. The inner diameter of the inner sleeve 58 is set to be slightly larger than the diameter of the tube 42 so that the tube 42 can be inserted. This inner sleeve 5
According to 8, the claw body 20 fitted in the opening 14 is restricted from moving in the direction in which the tube 42 is inserted and removed. That is, one end surface 22 of the claw body 20 facing the tube 42 in the insertion / removal direction comes into contact with one inner surface 14 a of the opening 14, and the other end surface 23 of the claw body 20 is connected to the other inner surface 14 b of the opening 14.
, So that the claw body 20 is slidably guided in a direction intersecting the insertion and removal direction of the tube 42.
4. Accordingly, it is possible to prevent the claw body 20 from moving in the insertion / removal direction of the tube 42. This allows
The tube 42, which has been prevented from falling out by the claw body 20, is prevented from moving (swinging) in the insertion / removal direction (restricted), and
Can be improved in sealing performance with respect to the pipe joint.

According to the above construction, the shape of each component is not complicated, and it can be easily formed of a resin material by a molding die and can be easily assembled. Therefore, a pipe joint having high quality and reliability and high sealing performance can be suitably formed of a resin material except for the sealing member. This allows areas where metal contamination is a problem, for example,
It can be suitably used in the fields of medicine and semiconductor. In addition, it can be easily manufactured by using a metal material, and particularly, one that is applied to a large-diameter pipe 42 can be easily manufactured, and versatility can be improved. In addition, the present invention is a pipe joint that prevents the pipe 42 (for example, a resin tube for air pressure) from coming off by sliding the lock sleeve 30.
It has a secure locking mechanism. In particular, since the claw body 20 does not swing in the axial direction (the direction in which the tube 42 is inserted and removed), its sealing property is high. That is, the swing of the pipe 42 caused by the change in the pressure of the pressure device connected to the pipe joint is reliably restricted, and the sealing performance can be improved.

Reference numeral 45 denotes a screw main body. The engaging portion 16 of the joint main body 10 is fitted inward while being sealed via an 'O'-ring 38, and the pipe joint itself is provided with a pressure device ( A screw portion 46 (male screw) for screwing to a screw (not shown) or the like is formed. In this embodiment, the engaging portion 16 is fitted to the screw main body 45 by fitting the above-mentioned enlarged diameter step 16a to the step 47 formed on the screw main body 45, and the joint main body 10 is fitted to the screw main body 45. Connected and fixed. In addition,
An outer portion of a portion in which a step portion 48 for receiving the 'O'-ring 38 is formed has a shape corresponding to a hexagonal bolt head 49.

The screw body 45 can be made of a metal material formed by cutting, for example, brass having good machinability or stainless steel having corrosion resistance.
As long as it has specifications such as strength enough to withstand use conditions, it is needless to say that it may be formed using a synthetic resin material (resin material). Further, in the present embodiment, the screw portion 46 is added to the joint main body 10 by the separate screw main body 45. However, the present invention is not limited to this. May be formed integrally with the joint body 10. That is, the method of connecting the pipe joint itself to other communication paths is not particularly limited, and various connecting means may be selectively adopted.

In the above embodiment, the two claws 2
Although 0 is provided, it is a matter of course that three or more claws 20 may be provided. Further, the pipe joint of the above embodiment has a fixing locking portion 16 formed at one end side for mounting equipment, but is not limited to this, and a pipe joint for relay, elbow, T type, Y type. And the like, and the size and shape of the claw body 20 and the shape and number of the claw portions 24 can be appropriately designed according to each fitting. I just need. As described above, various preferred embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and it goes without saying that many more modifications can be made without departing from the spirit of the invention. is there.

[0030]

According to the pipe joint of the present invention, the lock sleeve having the reduced-diameter inner peripheral portion which is fitted to the outer periphery of the joint main body,
The claws arranged slidably in the direction intersecting with the insertion and removal direction of the pipe in the opening of the joint body are moved, and the claws provided in the claws bite into the outer wall of the pipe,
The tube can be connected. According to this, the locking sleeve is slid to move the claw body to prevent the pipe from coming off, so that a reliable locking mechanism is provided. Thereby, swinging of the claw body in the insertion / removal direction is regulated, and a remarkable effect that sealing performance can be improved is achieved. Also, the shape of each component is not complicated, and can be easily formed by a molding die or the like. Therefore, a remarkable effect that a pipe joint having high quality and high reliability can be preferably and easily manufactured can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a pipe joint according to the present invention.

FIG. 2 is a cross-sectional view illustrating a shape of a claw body of the embodiment of FIG.

FIG. 3 is a sectional view showing an example of a conventional pipe joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Joint main body 12 Side peripheral wall 14 Opening 16 Locking part 19 Depression 20 Claw body 21 Curved surface 24 Claw part 25 Outer side surface 26 One end convex part 27 The other end convex part 30 Lock sleeve 32 Reduced diameter inner peripheral part 35 Inner surface taper part 40 Ring Seal member 42 pipe 45 screw body 50 spring part 58 inner sleeve

Continuation of the front page F term (reference) 3J106 AA06 AB01 BA01 BB01 BC04 BD01 BE11 BE40 CA13 EA03 EB02 EB05 EC03 EC07 ED22 EE12 EF04 EF05 EF07

Claims (5)

[Claims] 1. A joint body having a cylindrical side wall into which a pipe can be inserted, and having a plurality of openings provided at a plurality of locations on the side wall, and corresponding to the openings of the joint body. Are respectively slidably arranged in the opening in a direction intersecting with the direction of insertion and withdrawal of the pipe in the joint body, and are arranged so that the outer surface is exposed outward from the opening, A plurality of claw bodies projecting on the inner side facing the inside of the inserted pipe to bite into the outer wall of the inserted tube to prevent pulling out of the pipe, and are externally fitted to the joint body and moved in the pipe insertion / removal direction. The tube has a reduced diameter inner peripheral portion provided so as to be reduced in diameter at a middle portion in the pipe insertion / removal direction, and when the pipe is moved in one direction in the pipe insertion / removal direction, the diameter is reduced. The inner peripheral portion abuts on the outer surface of the claw body to move the claw body inward A lock sleeve that presses and slides the claws into the outer wall of the pipe; and constantly urges the claws to the outside of the joint body, and the lock sleeve is moved in the other direction in the pipe insertion / removal direction. Urging means for sliding the claw body out of the joint body to release the claw portion from biting into the outer wall of the tube when the reduced diameter inner peripheral portion does not contact the outer surface of the claw body And a ring-shaped seal member that is fitted inside the joint body behind the claw body and seals between an inner peripheral surface of the joint body and an outer peripheral surface of a pipe to be inserted. A pipe fitting characterized by the following. 2. The pipe joint according to claim 1, wherein a sliding direction of the claw body is a direction orthogonal to a pipe insertion / removal direction in the joint body. 3. The pipe joint according to claim 1, wherein said urging means is formed integrally with said claw body in a leaf spring shape. 4. The apparatus according to claim 1, wherein said urging means is an elastic member provided separately from said claw body.
Or the pipe joint according to 3. 5. An enlarged diameter step at the distal end of the joint body opposite to the part connected to the pipe by the claw body so as to be connected to another communication path so as to form a stepped portion. And a connecting portion formed on the side connected to the pipe by the claw body than the locking portion. 2. A step portion is formed so as to be able to be sealed via a seal member and a ring-shaped seal member.
The pipe joint according to 2, 3, or 4.