Conveying system

Abstract

To provide a conveying system capable of improving the meshing property of a pinion gear and a rack unit and prolonging the service life by improving the tooth flank strength with a simple constitution.SOLUTION: In the transport system 100 that moves a moving body by a rack-and-pinion method, the rack unit 110 in which rack teeth are continuous at a predetermined pitch is configured by disposing the movable rack 120 between the first fixed rack 111 and the second fixed rack 115 disposed at an interval on the transport path so as to be in contact with the first fixed rack 111, and the movable rack 120 is configured to be movable in a direction along the transport path by forming the gap S extending over the entire region in the tooth width direction of the rack teeth between the movable rack 120 and the second fixed rack 115.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a conveyance system that moves a moving body such as a conveyance carriage by a rack-and-pinion method.

Background Art

[0002] There has been known a conveyance system for conveying a moving body such as a conveyance carriage, which is configured to vertically convey the conveyance carriage while maintaining it in a horizontal state by the rack-and-pinion method, and horizontally convey the conveyance carriage along a travel rail extending horizontally at a predetermined level position (see, for example, Patent Document 1).

[0003] In the conveyance system described in Patent Document 1, a rack is arranged so as to extend in a vertical direction, a pinion gear that engages with the rack is provided on the conveyance carriage, and the conveyance carriage is configured to be vertically conveyed along the rack by rotationally driving the pinion gear. Further, by releasing the engagement of the pinion gear with the rack and separating the pinion gear from the conveyance path, the conveyance carriage can be horizontally conveyed along the travel rail extending in the horizontal direction.

[0004] In a conveyance system to which such a rack-and-pinion method is applied, it is necessary to intentionally provide backlash (a gap or play) between rack teeth and pinion teeth in order to allow smooth rotation of the pinion gear without difficulty. The reason for this is that if there is no backlash, the rack teeth and the pinion teeth interfere with each other, making it impossible to rotate the pinion gear. The backlash gap is set, for example, within a range of 0.1 to 0.2 mm.

[0005] Accordingly, if there is a phase shift between the rack teeth and the pinion teeth, the meshing between the rack teeth and the pinion teeth deteriorates, which causes noise and vibration, may shorten the service life of the device, and adversely affects the traveling of the conveyance carriage. In the transport system described in Patent Document 1, which transports a transport trolley vertically and horizontally, the transport trolley is transported horizontally to engage the pinion gear with the rack. At this time, if the phase of the pinion teeth is not within the range of the backlash gap with the rack teeth, the pinion gear cannot be engaged with the rack. Therefore, high-precision phase alignment of the pinion gear with respect to the rack is required, which leads to the problem of complicating the system and structure in order to recognize the precise rotational position of the pinion gear.

[0006] To address these problems, the applicant has proposed a transport system in which fixed rack teeth in a rack arranged at a predetermined pitch along the transport path are replaced with movable rack teeth in a portion of the rack, and the movable rack teeth are configured to be movable in a direction along the transport path such that the pinion teeth of the pinion gear can engage with and disengage from the movable rack teeth in the tooth width direction and tooth height direction of the movable rack teeth (see Patent Document 2). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 6896034 [Patent Document 2] Japanese Patent Publication No. 2023-115671 [Overview of the project] [Problems that the invention aims to solve]

[0008] In the transport system described in Patent Document 2, the operating range of the movable rack is set by a notch formed by the absence of fixed rack teeth in the tooth width direction. As a result, it has become clear that the tooth width of both the fixed rack teeth and the movable rack teeth is reduced, which can lead to a decrease in tooth surface strength, vibration and noise generation, and premature loss of function of the transport system. Furthermore, since the movable rack teeth are configured so that their tip surfaces are located on an arc-shaped surface centered on the pivot axis, it is difficult to arrange the movable rack teeth and fixed rack teeth in an optimal engagement relationship, and there is a risk that the meshing performance will decrease when the pinion gear moves between the movable rack teeth and the fixed rack teeth.

[0009] The present invention has been made based on the above circumstances, and aims to provide a transport system that can improve the meshing between the pinion gear and the rack unit with a simple configuration, and can also improve the tooth surface strength to extend the lifespan. [Means for solving the problem]

[0010] The present invention provides a transport system comprising a rack unit having rack teeth arranged to extend along a transport path and having rack teeth that are continuous at a predetermined pitch, and a movable body provided with a pinion gear that engages with the rack unit, wherein the movable body is moved along the transport path by rotationally driving the pinion gear, wherein the rack unit comprises a first fixed rack and a second fixed rack arranged at intervals along the transport path, and a movable rack arranged between the first fixed rack and the second fixed rack and configured to move in a direction along the transport path so that the pinion gear can engage and disengage, and the movable rack is configured such that a gap is formed between the movable rack and the second fixed rack at a position in contact with the first fixed rack, extending across the entire tooth width direction of the rack teeth, thereby solving the above problem. [Effects of the Invention]

[0011] According to the transport system described in claim 1, a gap is formed between the movable rack and the second fixed rack that extends across the entire tooth width of the rack teeth, thereby enabling the movable rack to move along the transport path. This allows for smooth engagement and disengagement of the pinion gear from the rack with a simple configuration, and also enables the rack teeth to receive force across their entire tooth width. As a result, the meshing between the pinion gear and the rack can be improved, and the lifespan can be extended by improving the tooth surface strength. Furthermore, since the movable rack can be configured to have the same specifications as the first and second fixed racks, the structure can be simplified in this respect as well.

[0012] According to the configuration described in claim 2, it becomes possible to properly set the interaction between the first fixed rack and the second fixed rack and the movable rack, and it is possible to avoid a decrease in meshing performance when the pinion gear moves between the movable rack and the first fixed rack or the second fixed rack. According to the configuration described in claim 3, when engaging the pinion gear with the movable rack, the movable rack swings away toward the pivot axis side which acts as the fulcrum, making it easier to engage the pinion gear with the movable rack. According to the configuration described in claim 4, when engaging the pinion gear with the rack unit and positioning it on the transport path, the pinion teeth of the pinion gear can be properly inserted into the tooth grooves between the rack teeth of the movable rack, making it possible to easily engage the pinion gear with the movable rack. According to the configuration described in claim 5, it is possible to use gravity to hold the movable rack at the limit of movement position, which is the position where it is in contact with the first fixed rack, and the device structure can be simplified. According to the configurations described in claims 6 and 7, when the pinion gear moves between the movable rack and the first fixed rack, the meshing performance does not decrease, and the moving object can be transported stably. According to the configurations described in Claim 8 and Claim 9, regardless of the moving direction of the transport carriage, the tooth surface of the movable rack that receives a reaction force from the pinion gear is only the tooth surface on the same side as the second fixed rack. Therefore, even if other portions are cut away to form a gap, the required tooth surface of the rack remains without being missing. This prevents a decrease in meshing performance when the pinion gear transfers between the movable rack and the first fixed rack, enabling stable conveyance of a moving body. [BRIEF DESCRIPTION OF THE DRAWINGS]

[0013] [Figure 1] FIG. 1 is a perspective view schematically showing the configuration of an example of the conveyance system according to the present invention. [Figure 2] FIG. 2 is a perspective view schematically showing a partial configuration of a rack unit together with a pinion gear. [Figure 3] FIG. 3 is a side view schematically showing a partial configuration of a rack unit together with a pinion gear. [Figure 4] FIG. 4 is a schematic diagram showing an outline of a partial configuration of a rack unit, as viewed from the tooth depth direction of rack teeth. [Figure 5A] FIG. 5 is a schematic diagram schematically showing a state when a pinion gear passes through a movable rack from below to above. [Figure 5B] FIG. 6 is a schematic diagram schematically showing a state when a pinion gear passes through a movable rack from above to below. [Figure 6A] FIG. 7 is a schematic diagram schematically showing the detachment operation of a pinion gear from a rack unit. [Figure 6B] FIG. 8 is a schematic diagram schematically showing the state of a movable rack when a pinion gear is detached from the rack unit. [Figure 7A] FIG. 9 is a schematic diagram schematically showing the re-engagement operation of a pinion gear to a rack unit. [Figure 7B] FIG. 10 is a schematic diagram schematically showing the state of a movable rack when a pinion gear is re-engaged to the rack unit. [DESCRIPTION OF EMBODIMENTS]

[0014] Hereinafter, a conveyance system according to an embodiment of the present invention will be described with reference to the drawings. For convenience of description, as shown in FIG. 1, an XYZ three-dimensional orthogonal coordinate system is defined to describe the structure of each part.

[0015] As shown in FIG. 1, a conveyance system 100 according to an embodiment of the present invention includes a vertical conveyance unit 101 that conveys a conveyance carriage as a moving body 130 along a vertical conveyance path extending in the Z direction, and a horizontal conveyance unit 105 that conveys the conveyance carriage along a horizontal conveyance path extending in the Y direction at a predetermined level position in the Z direction.

[0016] The vertical conveyance unit 101 includes a pair of support rails that are opposed to each other so as to extend along the vertical conveyance path at positions spaced apart in the X direction. To each of the support rails, for example, a rack unit 110 formed in a substantially prismatic shape and having rack teeth provided on one surface along the XZ plane is fixed so as to extend in the Z direction. The horizontal conveyance unit 105 includes travel rails 106 fixed to extend horizontally in the Y direction at predetermined level positions in the Z direction on each of the support rails 102.

[0017] On both sides of the conveyance carriage, a pinion gear 131 that is rotationally driven to be capable of forward and reverse rotation by an appropriate drive source and engages with the rack unit 110 is provided such that its rotation shaft extends in the X direction, and a guide roller 135 that travels along the support rail 102 is provided above the pinion gear 131. Reference numeral 136 in FIG. 1 denotes a wheel that is rotationally driven to be capable of forward and reverse rotation for horizontally conveying the conveyance carriage, and is provided so as to be movable forward and backward in the X direction. The pinion gear 131 and the guide roller 135 are provided so as to be movable forward and backward in the X direction. When the pinion gear 131 is moved in a direction approaching the conveyance carriage, the engagement between the pinion gear 131 and the rack unit 110 is released, and the pinion gear 131 is separated from the vertical conveyance path; at the same time, when the guide roller 135 is moved in a direction approaching the conveyance carriage along the X direction, the guide roller 135 is separated from the support rail 102, whereby horizontal conveyance of the conveyance carriage is enabled.

[0018] As shown in Figures 2 to 4, the rack unit 110 includes a first fixed rack 111 and a second fixed rack 115 arranged to be spaced apart in the Z direction on a vertical transport path, and a movable rack 120 arranged between the first fixed rack 111 and the second fixed rack 115 and configured to move in a direction along the vertical transport path so that the pinion gear 131 can engage and disengage. The first fixed rack 111, the second fixed rack 115, and the movable rack 120 are formed with the same specifications and have a plurality of rack teeth 112, 116, 121 extending in the X direction.

[0019] When the pinion gear 131 is not engaged, the movable rack 120 is restricted from moving downward in the vertical direction by contacting the first fixed rack 111, which is located downward in the Z direction, due to its own weight. This makes it possible to hold the movable rack 120 at the limit position, which is the position where it contacts the first fixed rack 111, using gravity, thereby simplifying the device structure.

[0020] The rack teeth 121 of the movable rack 120 are continuous with the rack teeth 112 of the first fixed rack 111 and the rack teeth 116 of the second fixed rack 115 at a predetermined pitch p when the movable rack 120 contacts the first fixed rack 111, and the tip surfaces of the rack teeth 121 are formed to be on the same plane as the respective tip surfaces of the rack teeth 112 of the first fixed rack 111 and the rack teeth 116 of the second fixed rack 115. This makes it possible to properly set the interaction between the first fixed rack 111 and the second fixed rack 115 and the movable rack 120, and makes it possible to stably transport the transport trolley by avoiding a decrease in meshing performance when the pinion gear 131 moves between the movable rack 120 and the first fixed rack 111 or the second fixed rack 115.

[0021] A gap S is formed between the movable rack 120 and the second fixed rack 115, extending across the entire tooth width direction of the rack teeth 121 and 116. The gap S is formed by cutting out either or both of the rack teeth 116 formed at the movable rack end of the second fixed rack 115 and the rack teeth 121 at the second fixed rack end of the movable rack 120, so that the tooth surface of the rack teeth 116 of the second fixed rack 115 on the side opposite to the movable rack 120 and the tooth surface of the rack teeth 121 of the movable rack 120 on the side opposite to the second fixed rack 115 remain. In this embodiment, the ends of the rack teeth 121 on the second fixed rack side of the movable rack 120 are formed at a position corresponding to the tooth root, and the rack teeth 116 formed on the movable rack side end of the second fixed rack 115 are cut out so that the tooth surface opposite to the movable rack 120 remains, thereby forming a gap S between the second fixed rack 115 and the movable rack 120. As a result, it is possible to reliably obtain a state in which the rack teeth 121 of the movable rack 120 and the rack teeth 116 of the second fixed rack 115 are continuous at a predetermined pitch p at the position where the movable rack 120 contacts the first fixed rack 111, and it is possible to avoid a decrease in meshing performance.

[0022] Preferably, the gap S is formed to be less than or equal to half the pitch p of the rack teeth 116 and 121. This ensures the range of motion of the movable rack 120 necessary to smoothly re-engage the pinion gear 131, which has been temporarily detached from the rack unit 110, with the rack teeth 121 of the movable rack 120, the rack teeth 112 of the first fixed rack 111, and the rack teeth 116 of the second fixed rack 115 are continuous at a predetermined pitch p at the position where the movable rack 120 contacts the first fixed rack 111. Therefore, the configuration facilitates the engagement and detachment of the pinion gear 131 from the rack unit 110, while ensuring tooth strength and enabling stable operation of the transport trolley. In this embodiment, the gap S is formed so that an amount of movement of the movable rack 120 corresponding to half a pitch (1 / 2p) of the rack teeth 121 is obtained.

[0023] In this embodiment, the movable rack 120 is pivotably mounted on a pivot shaft 125 located on the other side of the rack unit 110 and extending in the tooth width direction of the rack teeth 121. This allows the movable rack 120 to move along the transport path, and the pinion gear 131 can engage with and disengage from the movable rack 120 in either the tooth width direction (X direction) or the tooth height direction (Y direction) of the rack teeth 121.

[0024] The pivot shaft 125 is positioned on the first fixed rack 111 side relative to the lower end face, which is the first fixed rack side end face of the movable rack 120, in the direction along the transport path. As a result, when engaging the pinion gear 131 with the movable rack 120, the movable rack 120 swings away toward the pivot shaft 125, which acts as a fulcrum, making it easier to engage the pinion gear 131 with the movable rack 120.

[0025] In the transport system 100 according to this embodiment, the pinion gear 131 on the transport trolley is configured to be disengaged and reengaged from the rack unit 110. As shown in Figure 4, the rack teeth 121 of the movable rack 120 have chamfered portions 122 formed on the edge of the end face on the side to which the pinion gear 131 is accessed when the pinion gear 131 is reengaged from the rack unit 110, for example, by chamfering. This allows the pinion teeth 132 of the pinion gear 131 to enter the tooth grooves between the rack teeth 121 of the movable rack 120 well when the pinion gear 131 is engaged with the rack unit 110 and positioned on the transport path, making it possible to easily engage the pinion gear 131 with the movable rack 120. In this embodiment, the chamfered portion 122 is configured to have a tip shape in which two inclined surfaces intersect each other at the center of the rack teeth 121 in the Z direction. However, it may also be configured to have a unidirectional tip shape that slopes downward in the Z direction from the side to which the pinion gear 131 is accessed.

[0026] Furthermore, as shown in Figure 2, the pinion teeth 132 of the pinion gear 131 have chamfered portions 133 formed on the edges of the end faces on the access side to the rack unit 110, for example, by chamfering. The same applies to the chamfered portions 133 of the pinion gear 131; the chamfered portions 133 may be configured to have a tip shape in which two inclined surfaces intersect each other at the center of the pinion teeth 132 in the Z direction, or they may be configured to have a unidirectional tip shape that slopes upward in the Z direction from the access side to the rack unit 110 toward the inside.

[0027] In this transport system 100, the pinion gear 131 is rotated, causing the pinion teeth 132 of the pinion gear 131 to mesh with the rack teeth 112, 116, and 121 of the rack unit 110, thereby enabling the transport trolley to be transported vertically.

[0028] When the pinion gear 131 is moving on the first fixed rack 111 or the second fixed rack 115, the movable rack 120 is held in its limit position by contacting the first fixed rack 111 due to its own weight, and the rack teeth 121 of the movable rack 120 are in continuous contact with the rack teeth 112 of the first fixed rack 111 and the rack teeth 116 of the second fixed rack 115 at a predetermined pitch p. Therefore, when the pinion gear 131 moves from the first fixed rack 111 to the movable rack 120, the engagement of the pinion teeth 132 with the rack teeth 112 of the first fixed rack 111 is released, and then the pinion teeth 132 smoothly engage with the rack teeth 121 of the movable rack 120 without getting caught. The same applies when the pinion gear 131 moves from the second fixed rack 115 to the movable rack 120.

[0029] When the pinion teeth 132 are engaged with the rack teeth 121 of the movable rack 120, as shown in Figures 5A and 5B, the weight of the transport trolley applies a force that pushes the movable rack 120 against the first fixed rack 111. Therefore, regardless of the rotation direction of the pinion gear 131, the movable rack 120 remains held in its limit position without moving in conjunction with the rotation of the pinion gear 131. When the pinion gear 131 is moving from bottom to top on the movable rack 120, after the pinion teeth 132 disengage from the rack teeth 121 of the movable rack 120, the rack teeth 121 of the movable rack 120 are continuous with the rack teeth 116 of the second fixed rack 115 at a predetermined pitch p, so the pinion teeth 132 of the pinion gear 131 smoothly engage with the rack teeth 116 of the second fixed rack 115 without getting caught. Similarly, when the pinion gear 131 is moving from top to bottom on the movable rack 120, after the pinion teeth 132 disengage from the rack teeth 121 of the movable rack 120, the pinion teeth 132 of the pinion gear 131 smoothly engage with the rack teeth 112 of the first fixed rack 111 without getting caught.

[0030] As described above, when the transport trolley is transported vertically so as to pass over the movable rack 120, the movable rack 120 does not move regardless of the direction of movement of the transport trolley. Therefore, the rack teeth 121 of the movable rack 120 maintain a continuous state with the rack teeth 112 of the first fixed rack 111 and the rack teeth 116 of the second fixed rack 115 at a predetermined pitch p. For this reason, the transport trolley can be transported stably.

[0031] When transporting the transport trolley horizontally, to remove the pinion gear 131 from the vertical transport path, the pinion gear 131, which is moving from top to bottom on the second fixed rack 115 or from bottom to top on the first fixed rack 111, is temporarily stopped at a position where the pinion teeth 132 mesh with the rack teeth 116 in the end region of the second fixed rack 115. Then, the wheels 136 for horizontal transport are moved in the direction away from the transport trolley along the X direction and positioned directly above the running rail 106. At this time, the wheels 136 are separated from the running rail 106, and by rotating the pinion gear 131 in the direction in which the transport trolley descends, the pinion gear 131 is moved to a position where the pinion teeth 132 mesh with the rack teeth 121 of the movable rack 120, and the wheels 136 are brought into contact with the running rail 106. When the wheel 136 makes contact with the running rail 106, the load of the transport trolley that was on the pinion gear 131 is removed, and the load of the transport trolley is transferred to the wheel 136. With the wheel 136 in contact with the running rail 106, the pinion gear 131 is rotated in the direction that the transport trolley descends, causing the movable rack 120 to swing without moving the pinion gear 131 downwards, as shown in Figure 6A.

[0032] After stopping the rotation of the pinion gear 131, the pinion gear 131 is moved in the direction toward the transport trolley along the X direction, thereby disengaging the pinion teeth 132 from the rack teeth 121 of the movable rack 120 and removing the pinion gear 131 from the vertical transport path. At this time, since the load of the transport trolley on the pinion gear 131 is removed, the pinion gear 131 can be easily removed. Once the pinion gear 131 is removed, as shown in Figure 6B, the movable rack 120 swings downward due to its own weight and is held at the limit of movement position by contacting the second fixed rack 115. Furthermore, as the pinion gear 131 disengages, the guide roller 135 moves in the direction toward the transport trolley along the X direction, causing the guide roller 135 to disengage from the support rail 102, which enables the transport trolley to be transported horizontally along the running rail 106.

[0033] When transporting the transport trolley vertically again after horizontal transport, and positioning the pinion gear 131 on the vertical transport path to re-engage it with the rack unit 110, the transport trolley is transported horizontally until the pinion gear 131 is in a position corresponding to the movable rack 120 in the Y direction, at which point the transport trolley is stopped. Then, the pinion gear 131 is moved in the X direction away from the transport trolley to engage it with the movable rack 120. In this case, even if the phase of the teeth of the pinion teeth 132 and the rack teeth 121 of the movable rack 120 is misaligned, as shown in Figure 7A, chamfered portions 122 and 133 are formed on the end faces of the rack teeth 121 of the movable rack 120 and the end faces of the pinion teeth 132, and the movable rack 120 is swingable. Therefore, by moving the pinion gear 131 in the X direction, the phase of the teeth of the pinion teeth 132 and the rack teeth 121 of the movable rack 120 can be aligned, and the pinion teeth 132 can easily enter the tooth grooves between the rack teeth 121 of the movable rack 120. When engaging the pinion gear 131 with the movable rack 120, the pinion gear 131 may be rotated by half a pitch of the pinion teeth 132, or the pinion gear 131 may be moved in the X direction while rotating. In this case, the pinion teeth 132 and the rack teeth 121 of the movable rack 120 can be reliably engaged. If the chamfered portion 122 on the rack teeth 121 of the movable rack 120 and the chamfered portion 133 on the pinion teeth 132 of the pinion gear 131 are configured to have, for example, a unidirectional tip shape, then such an operation is not necessary. Alternatively, the position of the pinion teeth 132 may be sensed to avoid the non-engagement range.

[0034] Next, as shown in Figure 7B, with the pinion teeth 132 engaged with the rack teeth 121 of the movable rack 120, the pinion gear 131 is rotated in the direction that the transport trolley rises, causing the movable rack 120 to swing to its limit position and applying a load from the transport trolley to the pinion gear 131. In addition, the guide roller 135 is moved in the direction away from the transport trolley along the X direction to position the guide roller 135 on the support rail 102. As described above, when the movable rack 120 is held at the limit of movement position where it contacts the first fixed rack 111, the rack teeth 121 of the movable rack 120 are continuous with the rack teeth 112 of the first fixed rack 111 and the rack teeth 116 of the second fixed rack 115 at a predetermined pitch p. Therefore, by moving the wheels 136 in the direction approaching the transport trolley along the X direction and then retracting the wheels 136, the pinion gear 131 is rotated, allowing the pinion teeth 132 to smoothly mesh with the rack teeth 112 of the first fixed rack 111 or the rack teeth 116 of the second fixed rack 115 without getting caught, making it possible to stably transport the transport trolley vertically.

[0035] Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various design modifications can be made without departing from the present invention as described in the claims. For example, in the above embodiment, the gap is formed by cutting out a part of the second fixed rack, but the gap may also be formed by cutting out a part of each of the second fixed rack and the movable rack, or by cutting out a part of the rack teeth at the second fixed rack side end of the movable rack. Furthermore, although the above embodiment describes a configuration in which the pinion gear engages and disengages from the movable rack from the tooth width direction of the rack teeth, the pinion gear may also be configured to engage and disengage from the movable rack from the tooth height direction of the rack teeth. In addition, in a configuration in which the pinion gear engages and disengages from the movable rack from the tooth width direction of the rack teeth, it is not necessary for both the pinion teeth and the rack teeth of the movable rack to have chamfered portions; it is sufficient for either the pinion teeth or the rack teeth of the movable rack to have chamfered portions. Furthermore, although the above embodiment describes a configuration in which the movable rack is moved along the transport path by swinging, the movable rack may also be configured to slide along the transport path. Furthermore, although the above embodiment described a configuration in which a rack unit is provided on each of a pair of support rails that are positioned opposite each other at positions spaced apart in the X direction and extending along a vertical transport path, the rack units do not need to be positioned on both sides of the transport trolley, and may be positioned on one side of the transport trolley or in the center of the rear side of the transport trolley. Furthermore, although the above embodiment describes a configuration in which the transport trolley is transported vertically using a rack and pinion system, the transport trolley may also be configured to transport horizontally using a rack and pinion system. In this case, the movable rack should be pressed against the limit position by a spring or the like. [Explanation of Symbols]

[0036] 100 ··· Conveyor System 101... Vertical conveying section 102 ··· Support rail 105 ··· Horizontal conveying section 106... Running rails 110 ··· Rack Unit 111 ··· 1st Fixed Rack 112 ··· Rack teeth 115 ··· Second fixed rack 116 ··· Rack teeth 120 ··· Movable rack 121 ··· Rack teeth 122 ··· Chamfered section 125 ··· Oscillating axis 130 ··· Mobile vehicle (transport cart) 131... Pinion gear 132... Pinion teeth 133 ··· Chamfered section 135 ··· Guide roller 136 ... wheels S... Gap

Claims

1. A transport system comprising a rack unit having rack teeth arranged to extend along a transport path and continuous at a predetermined pitch, and a movable body provided with a pinion gear that engages with the rack unit, wherein the movable body is moved along the transport path by rotationally driving the pinion gear, The rack unit comprises a first fixed rack and a second fixed rack arranged at intervals along the transport path, and a movable rack positioned between the first fixed rack and the second fixed rack and configured to move in a direction along the transport path so that the pinion gear can engage and disengage. The conveying system is characterized in that, at a position where the movable rack is in contact with the first fixed rack, a gap is formed between the movable rack and the second fixed rack that extends across the entire tooth width direction of the rack teeth.

2. The movable rack is provided so as to be able to swing with respect to a pivot axis that extends in the tooth width direction of the rack teeth, The conveying system according to claim 1, characterized in that the movable rack is configured such that, at a position in contact with the first fixed rack, the tip surfaces of the rack teeth are located on the same plane as the tip surfaces of the rack teeth of the first fixed rack and the second fixed rack.

3. The movable rack is provided so as to be able to swing with respect to a pivot axis that extends in the tooth width direction of the rack teeth, The conveying system according to claim 1, characterized in that the pivoting shaft is located on the first fixed rack side with respect to the first fixed rack side end face of the movable rack in the direction along the conveying path.

4. The conveying system according to claim 1, characterized in that chamfered portions are formed on one or both of the edges of the end faces of the pinion teeth of the pinion gear and the edges of the end faces of the rack teeth of the movable rack.

5. The transport system according to claim 1, characterized in that the first fixed rack is positioned vertically below the second fixed rack and the transport path is configured to extend vertically.

6. The conveying system according to claim 1, characterized in that, at the position where the movable rack and the first fixed rack come into contact, the rack teeth of the movable rack and the rack teeth of the first fixed rack are formed to be continuous at a predetermined pitch.

7. The conveying system according to claim 1, characterized in that, at the position where the movable rack and the first fixed rack come into contact, the rack teeth of the movable rack and the rack teeth of the second fixed rack are formed to be continuous at a predetermined pitch.

8. The conveying system according to claim 1, characterized in that the gap is formed by cutting out the rack teeth formed on the movable rack side end of the second fixed rack so that at least the tooth surface on the side opposite to the movable rack remains.

9. The conveying system according to claim 8, characterized in that the movable rack is configured such that at least the tooth surface on the same side as the second fixed rack remains at the end of the rack teeth on the second fixed rack side.

Images