JP2005195452A - Nozzle holding mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nozzle holding mechanism capable of preventing the collision of an engaging protrusion. <P>SOLUTION: This nozzle holding mechanism is provided with a nozzle maintenance part 20 holding a dispensing nozzle 1 and movably supported along the arrangement direction, an engaging protrusion 28 to be a follower of a cam mechanism provided on each nozzle holding part, an adjusting axis 31 for engaging each of the engaging protrusions with a plurality of spiral cam grooves 32 provided on the perimeter side and adjusting the intervals between the nozzle holding parts 20, and a driving means 40 for rotating the adjusting axis. Before the engaging protrusion arrives at the end part of the cam groove, a regulating means 50 for regulating the rotation of the adjusting axis in the arrival direction is provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a nozzle holding mechanism that adjusts the spacing of a plurality of nozzles.

A dispensing apparatus for dispensing liquid includes a plurality of dispensing nozzles and a nozzle holding mechanism that variably adjusts the interval of each dispensing nozzle.
The dispensing nozzle is a so-called pipette, which is supported in a vertical state and has a negative pressure in the interior thereof, so that the target liquid is sucked from its lower end and is transported to a predetermined position. The liquid that has been sucked in with the positive pressure inside is discharged.
The nozzle holding mechanism supports a plurality of the above-mentioned dispensing nozzles arranged horizontally at a uniform interval, and has a function of adjusting the interval between the dispensing nozzles according to the arrangement of the liquid suction object and the discharge object. ing.

Such a conventional nozzle holding mechanism includes a plurality of nozzle holding portions that individually hold dispensing nozzles, a support shaft that supports the plurality of nozzle holding portions arranged in a horizontal direction, and a cam provided in each nozzle holding portion. An engagement projection that is a follower of the mechanism, an adjustment shaft that engages each engagement projection with a plurality of helical cam grooves provided on the outer peripheral surface thereof, and adjusts the distance between the holding bodies; and Driving means for performing rotational driving (see, for example, Patent Document 1).
When the adjustment shaft is driven to rotate, the nozzle holding mechanism contacts the inclined inner surface of the cam groove and is guided in the center line direction (horizontal direction) of the adjustment shaft. Each nozzle holding part is guided in the horizontal direction according to the inclination of the cam groove set as appropriate individually, so that only the interval length is adjusted while maintaining the uniform interval of each nozzle holding part. It is like that.
Japanese Patent No. 2528297

However, in the above conventional example, when the adjustment shaft rotates excessively for some reason, the engagement protrusion collides with the end of the cam groove, and the engagement protrusion may be deformed or damaged. If the engaging protrusion is deformed or damaged, it becomes impossible to accurately position the dispensing nozzle at the predetermined position, causing a dispensing error or excessive sliding with the cam groove. This causes inconveniences such as a decrease in durability and noise due to wear.
An object of the present invention is to prevent damage to the engaging protrusions of the nozzle holding portion.

  According to the first aspect of the present invention, there are provided a nozzle holding portion for holding a dispensing nozzle for sucking and discharging a liquid and a plurality of which are supported so as to be movable along the arrangement direction, and a cam provided in each nozzle holding portion. An engagement projection that is a follower of the mechanism, an adjustment shaft that engages each engagement projection with a plurality of helical cam grooves provided on the outer peripheral surface thereof, and adjusts the distance between the holding bodies; and And a driving unit that performs rotational driving, and before the engaging projection reaches the end of the cam groove, a regulating unit that regulates the rotational driving of the adjusting shaft in the reaching direction is provided.

In the above configuration, when the engagement protrusion provided on each of the plurality of nozzle holding portions is engaged with the cam groove of the adjustment shaft and the adjustment shaft is rotated, the engagement protrusion is guided by the cam groove. Accordingly, each nozzle holding portion moves along the center line direction of the adjustment shaft. Each nozzle holding portion has a moving amount with respect to the rotation angle of the adjusting shaft set by the groove pitch of the corresponding cam groove, and the interval between the dispensing nozzles is adjusted according to each set moving amount.
If the rotational driving force is still applied to the adjusting shaft even when the engaging protrusion moves to the beginning or end of the cam groove, the restricting means causes the engaging protrusion to reach either end. Before turning, the rotation of the adjusting shaft is restricted and stopped. Thereby, the collision of the engaging protrusion with the cam groove end is avoided.

The invention according to claim 2 has the same configuration as that of the invention according to claim 1, and the restricting means includes a locked portion provided on the adjustment shaft or an interlocking shaft interlocking with the adjustment shaft, and an adjustment shaft. And a locking part that stops the locked part at a predetermined rotation angle.
In such a configuration, even when the engagement protrusion moves to the beginning or end of the cam groove, if the rotational driving force is still applied to the adjustment shaft, the locked portion is locked to the locking portion. The rotation of the adjusting shaft is stopped before the engaging protrusion reaches one of the ends.
In the above configuration, an interlocking shaft that interlocks with the adjustment shaft does not have to be provided, but when provided, a locked portion may be provided on the interlocking shaft. In that case, the rotation of the interlocking shaft is restricted, and the rotation of the adjustment shaft is also restricted in conjunction with it.

The invention described in claim 3 has the same configuration as that of the invention described in claim 2, and is provided with an interlocking shaft having a speed change means between the adjusting shaft and the restricting means includes a locked portion on the interlocking shaft. The structure of providing is taken.
In such a configuration, even when the cam groove is formed over a range of one or more rotations of the adjustment shaft, the speed change means causes the rotation of the entire rotation of the cam groove of the adjustment shaft to be less than one rotation of the interlocking shaft. By decelerating to this range, it is sufficient to restrict the movement of the locked portion that can be moved only within the range of one round. Therefore, the locking portion prevents the locked portion from moving at a predetermined position. If it has only a structure, its function can be fulfilled, and the restriction means can be simplified.

The invention described in claim 4 has the same configuration as that of the invention described in claim 1, and further includes an endless track for transmitting the rotational driving force to the adjustment shaft, and the restricting means is a locked portion provided on the endless track. And a locking portion that stops the locked portion at a predetermined rotation angle of the adjustment shaft.
In the above configuration, by providing the endless track, even when there are a plurality of adjusting shafts, it is possible to simultaneously apply the rotational driving force. And by providing the to-be-latched part in the endless track and making the endless track stationary, the rotation of each adjustment shaft can be regulated at the same time all at once.

The invention according to claim 5 has the same configuration as that of the invention according to any one of claims 2 to 4, and an adjusting means for adjusting the stationary position of the locked portion on the locking portion. The structure of providing is taken.
In the above configuration, the locking portion is moved and adjusted by the adjusting means, thereby adjusting the locking position of the locked portion. Accordingly, the stationary position of the engagement protrusion with respect to the cam groove is adjusted to an appropriate position.

According to the first aspect of the present invention, since the engaging projection for moving the nozzle holding portion has the restricting means for restricting the rotational drive of the adjusting shaft before reaching the end of the cam groove, It is possible to effectively avoid deformation and breakage of the engaging protrusion due to a collision accident due to excessive rotation, improve the maintainability of the mechanism, and extend the life. In addition, it is possible to prevent wear caused by sliding of the deformed engagement protrusion, and to extend the life of the mechanism from this viewpoint. Furthermore, it is possible to suppress the generation of noise by avoiding the sliding of the engaging protrusions.
In addition, since the deformation of the engaging protrusion is avoided, the positioning of the dispensing nozzle can always be maintained with high accuracy.

  In the invention according to claim 2, since the restricting means is configured by the locked portion and the locking portion for locking the locked portion, the configuration of the restricting means can be simplified, and the productivity of the mechanism is increased. It becomes possible to improve.

  According to the third aspect of the invention, since the interlocking shaft having the speed change means is provided between the adjustment shaft and the cam groove, the cam groove is formed over a range of one rotation or more of the adjustment shaft. The speed change means can avoid the rotation of the interlocking shaft more than one round, and if the locking portion has only a structure that prevents the locked portion from moving at a predetermined position, the function can be achieved. Therefore, the configuration of the restricting means can be simplified and the productivity of the mechanism can be improved, rather than the configuration in which the rotation is further controlled by a predetermined amount after a plurality of rotations. Is possible.

  In the invention according to claim 4, since the endless track is provided and the locked member is provided on the endless track, it becomes possible to simultaneously apply a rotational driving force to a plurality of adjustment shafts. It becomes possible to regulate the rotation of the shaft all at the same time.

  Since the invention according to claim 5 has the adjusting seed means for adjusting the position of the locking portion, the locking position of the locked portion can be adjusted via the adjusting means. The stationary position of the engaging protrusion with respect to the cam groove can be adjusted to an appropriate position. Therefore, the adjustment shaft can be stopped more precisely, the collision accident of the engagement protrusion can be prevented more effectively, the maintenance of the mechanism is improved, the life of the mechanism is extended, the noise is reduced, and the dispensing nozzle It becomes possible to stabilize the positioning accuracy.

(Overall configuration of the embodiment)
A nozzle holding mechanism 10 according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a peripheral configuration for holding the dispensing nozzle 1 of the nozzle holding mechanism 10.
The nozzle holding mechanism 10 is mounted on a dispensing device that sucks and collects a liquid material from a plurality of collection containers and discharges the liquid material to a plurality of corresponding discharge containers. This dispensing apparatus performs suction collection with respect to a plurality of collection containers arranged at uniform intervals in a state in which a plurality of dispensing nozzles 1 that perform suction and discharge of a liquid substance are aligned with the intervals of the collection containers. Then, this time, the liquid material collected by aligning the intervals of the dispensing nozzles to a plurality of discharge containers arranged at uniform intervals is discharged.
The collection container and the discharge container may be arranged at different pitches between the containers. Therefore, the nozzle holding mechanism 10 holds a plurality of dispensing nozzles while maintaining a uniform interval state. A function for changing and adjusting the interval length is required.

  In order to fulfill the above function, the nozzle holding mechanism 10 serves as a nozzle holding unit that holds the dispensing nozzles 1 individually and is arranged side by side in two rows of four, and is movably supported along the arrangement direction. The nozzle holders 20, the engagement protrusions 28 provided on the nozzle holders 20, and the engagement protrusions 28 are engaged with a plurality of spiral cam grooves 32 (see FIG. 3) provided on the outer peripheral surface thereof. The adjustment shaft 31 that adjusts the interval between the nozzle holders 20, the frame 11 that rotatably supports the adjustment shaft 31, and the rotation mechanism 40 that serves as a drive unit that drives the adjustment shaft 31 to rotate (see FIGS. 4 and 4). 5), and before the engaging projection 28 reaches the end of each cam groove 32, there is a restricting means 50 (see FIG. 4) for restricting the rotational drive of the adjusting shaft 31 in the reaching direction.

In the following description, each dispensing nozzle 1 is supported in a vertical state by a nozzle holding mechanism 10 in a state in which a dispensing device is installed on a horizontal plane and is used normally, and each nozzle holding body. 20 are arranged along the horizontal direction.
In the following description, the arrangement direction of the plurality of nozzle holders 20 is defined as the X-axis direction, and the direction along the longitudinal direction of the dispensing nozzle 1 that is orthogonal to the X-axis direction and is held by each nozzle holding unit 20 is Z. A direction perpendicular to the X-axis direction and the Z-axis direction is taken as a Y-axis direction.
In addition, four adjustment shafts 31 are provided, and all of the adjustment shafts 31 are arranged so as to be parallel to the X-axis direction, and two nozzles arranged in the Z-axis direction are paired to hold four nozzles. While supporting the body 20, two sets of the adjustment shafts 31 are arranged close to each other along the Y-axis direction.

(Dispensing nozzle)
The dispensing nozzle 1 is an internal hollow tubular body, and is formed in a shape in which the outer diameter of the lower end portion is narrowed down toward the tip, and the inside of the dispensing nozzle 1 is negatively pressurized at the upper end portion. Alternatively, it is connected to an intake / exhaust means (not shown) that performs suction and discharge by switching to a positive pressure.

(Nozzle holder)
Each nozzle holding body 20 is supported in a state where an upper portion and a lower portion thereof are passed through a set of adjustment shafts 31, and can move in the X-axis direction along the adjustment shafts 31.
Each nozzle holding body 20 includes a lifting mechanism 21 that supports the dispensing nozzle 1 so as to be movable along the Z-axis direction at one end in the Y-axis direction and moves and positions the dispensing nozzle 1 along the Z-axis direction. I have.
As described above, the four nozzle holders 20 are supported side by side in the X-axis direction by the set of adjustment shafts 31, and each of the four nozzle holders 20 in the same set is the same. In the Y-axis direction, the dispensing nozzle 1 is supported so as to be movable up and down by support collars 25 and 26 extending toward the nozzle holder 20 that is the other set. In addition, each group of nozzle holders 20 is arranged such that the dispensing nozzles 1 to be supported are alternately arranged in a line along the X-axis direction for each group. In addition, the X-axis direction width | variety is each set so that each support collar part 25 and 26 is narrower than the adjustment axis | shaft 31 side of the nozzle holding body 20, and as mentioned above, the dispensing nozzle 1 is arranged alternately for every group. Thus, the nozzle holder 20 can be arranged in a concentrated manner at an interval narrower than the width on the adjustment shaft 31 side.

The lifting mechanism 21 constitutes a so-called ball screw mechanism. That is, a male screw is formed on the outer peripheral surface of the screw shaft 22 and is rotatably supported, and a moving body 23 that engages with the male screw of the screw shaft 22 and moves along the screw shaft 22 by the rotation. And a drive motor 24 that rotationally drives the screw shaft 22 via a transmission belt (not shown). The screw shaft 22 is disposed adjacent to the dispensing nozzle 1 in a state along the Z-axis direction, and the moving body 23 is connected to the dispensing nozzle 1.
With this configuration, the elevating mechanism 21 moves the dispensing nozzle 1 up and down by rotating the screw shaft 22 forward or backward by driving the drive motor 24 and moving the moving body 23 in both directions along the Z-axis direction. Can do.

  FIG. 2 is an explanatory view showing an engagement state between the nozzle holder 20 and the adjustment shaft 31 as seen from the direction along the Z-axis direction. Further, as described above, each nozzle holder 20 is provided with a circular through hole portion 27 into which the adjustment shaft 31 is inserted at the upper portion and the lower portion thereof, and the radial direction is provided inside the through hole portion 27. An engaging projection 28 is provided so as to project toward the center side (see FIG. 3). The engaging protrusion 28 is mounted in a protruding state so that the tip end portion thereof enters a cam groove 32 described later, and the outer diameter thereof is close to the groove width of the cam groove 32 within a possible range. Is set.

(Adjustment axis)
The adjustment shaft 31 will be described with reference to FIG. FIG. 3 is an explanatory diagram showing the relationship between each cam groove 32 and each nozzle holder 20 as viewed from the direction along the Y-axis direction.
The four adjustment shafts 31 are supported at both ends by the frame 11 so as to be arranged at positions corresponding to the vertices of the rectangle developed on the YZ plane. Each of the adjustment shafts 31 is supported in a state along the X-axis direction and rotatable about itself. The four nozzle holders 20 are supported for each of the adjustment shafts 31 having a unit of two pairs positioned at both ends of each of the vertical sides of the rectangle.

On the outer peripheral surface of the adjustment shaft 31, a spiral cam groove 32 corresponding to each nozzle holding body 20 is formed, and as described above, the engagement protrusion 28 provided on each nozzle holding body 20 is provided. Each nozzle holder 20 can be moved along the axial direction by the rotation operation of the adjusting shaft 31 because it is engaged in the state of entering the cam groove 32.
The adjusting shaft 31 has a predetermined groove pitch set for each cam groove 32 in order to be able to change and adjust the interval width while maintaining the uniform state of the intervals of the nozzle holding portions 20. Yes.

In the nozzle holding mechanism 10 according to the present embodiment, for each set of adjustment shafts 31, when the nozzle holding bodies 20 are set to the minimum interval, substantially the middle position (four in the longitudinal direction) of the adjustment shafts 31. The nozzle holder 20 is guided so as to gather at a position between the second and third nozzle holders 20). For this reason, among the cam grooves 32 corresponding to the four nozzle holders 20, the first and second cam grooves 32 from the left in FIG. The groove pitch of the first cam groove 32 far from the gathering position is set larger than that of the second cam groove 32. Further, for the third and fourth cam grooves 32 from the left, a spiral cam groove 32 is formed in the direction of the right screw, and the fourth cam groove 32 far from the gathering position is more than the third cam groove 32. The groove pitch is set large.
The ratio of the groove pitch is set equal to the distance ratio to the collection position of each nozzle holder 20.

  In addition, about the two adjustment shafts 31 for every group, since the same displacement is provided about each nozzle holding body 20 to support, the same cam groove is formed. On the other hand, for the adjustment shafts 31 having different sets, the set positions of the nozzle holders 20 are slightly different due to the structure in which the dispensing nozzles 1 are alternately arranged in the X-axis direction for each set. Cam grooves are formed at the groove pitch to be gathered.

(Rotating mechanism)
The rotation mechanism 40 will be described with reference to FIGS. FIG. 4 is a perspective view showing a detailed configuration of the front of the nozzle holding mechanism 10, and FIG. 5 is a rear view of the nozzle holding mechanism 10.
The rotation mechanism 40 is stretched between four pulleys 41 and a toothed pulley 41 having a uniform outer diameter (effective diameter) that is fixedly installed at the end of each adjustment shaft 31 on the back side of the nozzle holding mechanism 10. A timing belt 42 as a grooved endless track, a tension roller 43 that applies tension to the timing belt 42, and a driven pulley provided at an end of the adjustment shaft 31 on the front side of the nozzle holding mechanism 10. 44, a drive motor 45 serving as a rotational drive source for each adjustment shaft 31, a drive pulley 46 fixedly mounted on the output shaft of the drive motor 45, and a drive spanned between the drive pulley 46 and the driven pulley 44. Timing belt 47.
With this configuration, when the drive motor 45 is driven, torque is transmitted between the drive pulley 46 and the driven pulley 44 in accordance with the gear ratio, and torque is transmitted to one adjusting shaft 31. The adjustment shaft 31 is rotationally driven through the timing belt 42 in the same direction and at the same rotational speed.

(Regulatory measures)
The restricting means 50 will be described with reference to FIG. The restricting means 50 is a shift gear that is interlocked with the braking pulley 51 via a braking timing belt 53 and a braking pulley 51 that is fixedly mounted on an end of the adjustment shaft 31 on the front side of the nozzle holding mechanism 10. A transmission pulley 52 as a means, a restricting projection 54 as a locked portion that is fixedly mounted on the transmission pulley 52 and extends outward in the rotational radius direction, and the transmission pulley 52 in the counterclockwise direction in FIG. A first restricting member 55 as a locking portion that restricts further rotation at a rotation angle position when rotating, and further rotation at a rotation angle position when the transmission pulley 52 rotates clockwise. And a second regulating member 56 as a locking portion to be regulated.

Incidentally, each of the cam grooves 32 described above is formed in a range corresponding to two rotations of the adjustment shaft 31 from the start end to the end thereof, and the phases of the engagement protrusions 28 with respect to the cam grooves 32 are all. Installed to be equal. That is, all the engaging projections 28 are set to be simultaneously positioned at the start end portion and simultaneously positioned at the end portion thereof with respect to all the cam grooves 32.
The speed of the speed change pulley 52 is 2.5 times that of the restriction pulley 51. In other words, the transmission gear 52 is set to have a gear ratio so that the entire rotation range of the adjustment shaft 31 defined by the cam groove 32 is accommodated within one rotation pulley.

Then, the first restricting member 55 is provided in a state where each engaging projection 28 reaches the start end of the cam groove 32 when the adjustment shaft 31 rotates in the direction from the terminal end of the cam groove 32 toward the start end. At this position, the transmission pulley 52 is arranged so as to abut against the restricting projection 54 and no longer rotate.
In addition, the second restricting member 56 is configured so that when the adjusting shaft 31 rotates in a direction from the start end portion of the cam groove 32 toward the end portion side, each engagement protrusion 28 is just before reaching the end portion of the cam groove 32. At this position, the transmission pulley 52 is arranged so as to abut against the restricting projection 54 and no longer rotate.

In the above configuration, when the adjusting shaft 31 rotates in a predetermined direction to a predetermined angle, the transmission pulley 52 also rotates from the braking pulley 51 via the braking timing belt 53. Then, when the rotation is performed to some extent, the restriction projection 54 of the transmission pulley 52 comes into contact with the first restriction member 55 and cannot be further rotated. When the rotation of the speed change pulley 52 is restricted, the rotation is restricted for all the adjusting shafts 31 that are linked via the timing belt 53 and the braking pulley 51.
When the adjustment shaft 31 rotates in the reverse direction to a predetermined angle, the transmission pulley 52 also rotates in the reverse direction. Then, after a certain degree of rotation, no further rotation drive can be performed due to the contact of the restricting projection 54 with the second restricting member 56, and further, all the adjusting shafts 31 that are interlocked rotate in the reverse direction. Will be regulated.
As a result, each of the engaging protrusions 28 is prevented from colliding with the start or end of each cam groove 32.

Each of the regulating members 55 and 56 is provided with adjusting means including elongated holes 55a and 56a that can be moved and positioned along the tangential direction of the rotational movement direction of the regulating projection 54, and fastening screws 55b and 56b, respectively. It has been. Then, by loosening the fastening screws 55b and 56b, the regulating members 55 and 56 can be moved and adjusted along the elongated holes 55a and 56a, and the locking position of the regulating projection 54 can be adjusted.
For this reason, it is possible to adjust the stationary position of each adjusting shaft 31 to a more appropriate position by this adjusting means, and it is possible to more effectively prevent the engagement protrusion 28 from being damaged due to a collision accident.

(Explanation of nozzle holding mechanism operation)
The nozzle holding mechanism 10 adjusts the interval between the dispensing nozzles 1 so that the width is equal to that of the collection container when the liquid substance is sucked in each dispensing nozzle 1. That is, the drive motor 45 of the adjustment mechanism 40 is driven to rotate each adjustment shaft 31 and move each nozzle holder 20 in the X-axis direction. And when each dispensing nozzle 1 becomes an appropriate space | interval, the drive motor 45 is stopped.
Further, the height of the tip position of the dispensing nozzle 1 is adjusted by the drive motor 24 of the lifting mechanism 21 for each nozzle holder 20. Then, the inside of the dispensing nozzle 1 is set to a negative pressure by the intake / exhaust means, and the liquid material is sucked and collected from the tip portion.

Next, when the collected liquid substance is sucked, the interval between the dispensing nozzles 1 is adjusted so as to have the same width as the discharge container. That is, each adjusting shaft 31 is rotated by the adjusting mechanism 40, and each dispensing nozzle 1 is set to an appropriate interval.
Then, for each nozzle holder 20, the height of the tip position of the dispensing nozzle 1 is adjusted by the lifting mechanism 21, and the inside of the dispensing nozzle 1 is made positive pressure by the intake / exhaust means, and the liquid material starts from the tip portion. Is discharged.

  In the interval adjusting operation of each dispensing nozzle 1, due to some factor (for example, malfunction due to a control error or the like), the engagement protrusions 28 on the 28th floor toward the start or end of the cam groove 32 are used. If the drive motor 45 does not stop, the restricting protrusion 54 of the restricting means 50 comes into contact with the first restricting member 55 or the second restricting member 56, and the engaging protrusion 28 is the start end of the cam groove 32 or Before colliding with the terminal portion, the rotation of each adjustment shaft 31 is stopped.

(Effect of nozzle holding mechanism)
As described above, in the nozzle holding mechanism 10, the restricting protrusion 54 of the restricting means 50 abuts on the first or second restricting members 55 and 56 in advance, and the engaging protrusion 28 is the start end or end of the cam groove 32. Since the rotation of each adjusting shaft 31 is stopped before it collides with a part, deformation and breakage of the engaging projection 28 due to a collision accident can be effectively avoided, the maintainability of the mechanism is improved, and the service life is extended. Is possible. It is possible to prevent wear caused by the sliding of the deformed engagement protrusion 28 and to extend the life of the mechanism from this viewpoint. Furthermore, the occurrence of noise can be suppressed by avoiding the sliding of the engaging protrusions 28.
Furthermore, by avoiding the deformation of the engagement protrusion 28, the dispensing nozzle 1 can always be positioned with high accuracy.

(Other)
The adjustment shaft 31 provided with the restriction pulley 51 of the restriction means 50 may be any of the four, but is more preferably provided on the adjustment shaft 31 to which torque is transmitted from the rotation mechanism 40 most recently. This is because the braking force can be applied at a position closest to the drive source.
Further, in the present embodiment, a transmission pulley 52 as a transmission means is provided, and the rotation of each adjustment shaft 31 is controlled by restricting the rotation of the interlocking shaft (rotation support shaft of the transmission pulley 52) that is interlocked with the adjustment shaft 31. However, for example, if the rotation range of the adjustment shaft 31 does not reach a plurality of rotations, but is within the range of one rotation, the adjustment shaft 31 is not restricted by the transmission means. It is good also as a structure which provides a process protrusion and controls this.

(Other examples of regulating means)
The restricting means is not limited to the structure of the restricting means 50 as long as each adjusting shaft 31 is stopped at a predetermined position to avoid a collision between the engaging projection 28 and the end of the cam groove. An example of another restricting means 50A that can be used in place of the restricting means 50 will be described below.
The restricting means 50A includes a stopper member 51A having a width wider than the timing belt 42 fixedly provided in the middle of the timing belt 42 of the rotation mechanism 40, and movement of the stopper member 51A in one direction by the timing belt 42 at a predetermined position. And a second restriction member 53A for restricting movement of the stopper member 51A in the other direction by the timing belt 42 at a predetermined position.

Each of the restricting members 52A and 53A includes a concave portion or a passage hole having a width that allows the timing belt 42 to pass therethrough and cannot pass the stopper member 51A, and has a structure that allows only the timing belt 42 to pass therethrough. .
The first restricting member 52 </ b> A is positioned before each engaging projection 28 reaches the start end of the cam groove 32 when each adjustment shaft 31 rotates in the direction from the terminal end of the cam groove 32 toward the start end. In this position, the stopper member 51A is disposed so as to contact the first restricting member 52A so that the timing belt 42 is not further conveyed.
In addition, the second restricting member 53 </ b> A is located just before each engaging projection 28 reaches the terminal end of the cam groove 32 when each adjusting shaft 31 rotates in the direction from the starting end of the cam groove 32 toward the terminal end. At this position, the stopper member 51A is disposed so as to abut against the second restricting member 53A and prevent the transmission pulley 52 from rotating any further.

In the above configuration, when each adjusting shaft 31 rotates in a certain direction to a predetermined rotation angle, the stopper member 51A moves in a certain direction along with the conveyance of the timing belt 42, and comes into contact with the first regulating member 52A when it moves to some extent. It becomes impossible to perform further rotational driving. Accordingly, the rotation of all the adjustment shafts 31 is restricted. Further, the stopper member 51A moves in a certain direction along with the conveyance of the timing belt 42, and when it moves to some extent, it comes into contact with the second restricting member 53A and cannot be rotated further. Therefore, the rotation in the reverse direction is restricted for all the adjusting shafts 31.
As a result, each of the engaging protrusions 28 is prevented from colliding with the start end or the end of each cam groove 32.

  Each of the regulating members 52A and 53A is also provided with adjusting means including elongated holes 55A and 57A that can be moved and positioned along the moving direction of the stopper member 51A, and fastening screws 54A and 56A. Then, by loosening the fastening screws 54A and 56A, the regulating members 52A and 53A can be moved and adjusted along the elongated holes 55A and 57A, and the locking position of the stopper member 51A can be adjusted. Thereby, it becomes possible to adjust the stationary position of each adjusting shaft 31 to a more appropriate position, and it is possible to more effectively prevent the engagement protrusion 28 from being damaged due to a collision accident.

It is a perspective view of the structure of the periphery holding the nozzle of a nozzle holding mechanism. It is explanatory drawing which shows the engagement state of the nozzle holding body and adjustment shaft seen from the direction along the Z-axis direction. It is explanatory drawing which shows the relationship between each cam groove seen from the direction along the Y-axis direction, and each nozzle holding body. It is a perspective view which shows the detailed structure of the front of a nozzle holding mechanism. It is a rear view of a nozzle holding mechanism. It is a rear view of the nozzle holding mechanism which shows the other example of a control means.

Explanation of symbols

1 Dispensing nozzle 10 Nozzle holding mechanism 20 Nozzle holder (nozzle holding part)
28 Engagement protrusion 31 Adjustment shaft 32 Cam groove 40 Rotation mechanism (drive means)
42 Timing belt (endless track)
50 restriction means 52 speed change pulley (speed change means)
54 Restriction protrusion (locked part)
55, 52A First restriction member (locking portion)
56, 53A Second restriction member (locking portion)

Claims (5)

A nozzle holding unit that holds a dispensing nozzle that performs suction and discharge of liquid and that is supported so that a plurality of the nozzles can move along the alignment direction;
An engaging projection that is a follower of a cam mechanism provided in each nozzle holding portion;
An adjusting shaft that adjusts the spacing between the nozzle holding portions by engaging the engaging protrusions with a plurality of helical cam grooves provided on the outer peripheral surface;
Drive means for rotating the adjustment shaft,
A nozzle holding mechanism characterized in that a restricting means for restricting the rotational drive of the adjusting shaft in the reaching direction is provided before the engaging protrusion reaches the end of the cam groove. The restricting means includes a locked portion provided on the adjusting shaft or an interlocking shaft interlocking with the adjusting shaft, and a locking portion that stops the locked portion at a predetermined rotation angle of the adjusting shaft. The nozzle holding mechanism according to claim 1. While providing an interlocking shaft having a transmission means between the adjustment shaft,
The nozzle holding mechanism according to claim 2, wherein the restricting means is provided with the locked portion on the interlocking shaft. An endless track for transmitting a rotational driving force to the adjustment shaft;
The said restricting means is provided with the to-be-latched part provided in the said endless track | orbit, and the latching | locking part which stops the said to-be-latched part with the predetermined | prescribed rotation angle of the said adjustment shaft. Nozzle holding mechanism. The nozzle holding mechanism according to any one of claims 2 to 4, wherein an adjustment means for adjusting a stationary position of the locked portion is provided in the locking portion.

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