Servo driver housing structure and traction motor

Abstract

This provides a servo driver housing structure with higher durability. [Solution] The housing structure 100 of the servo driver 11 mounted on the trolley 10 comprises a housing 101 that houses the control device and has a bottom wall 102 and a peripheral wall 103, and a bracket 110 made of a bent metal plate and provided on the bottom wall 102 of the housing 101 for fixing the housing 101 to the trolley 10. The bracket 101 comprises a bottom plate portion 111 having a fixing portion 117 that is placed on and fixed to the mounting surface of the trolley 11, a rising portion 112 that extends upward from the bottom plate portion 111, and a support plate portion 113 that extends substantially horizontally from the upper end of the rising portion 112, is connected to the bottom wall 102, and supports the housing 101. A curved notch portion 116 is formed at the edge of the mountain-fold bent portion 115 between the rising portion 112 and the support plate portion 113.

Description

Technical Field

[0001] The present invention relates to a housing structure of a servo driver mounted on a traveling vehicle and a traveling bogie.

Background Art

[0002] Conventionally, traveling bogies such as autonomous mobile robots (AMRs) and automated guided vehicles (AGVs) have been used to automatically transport articles in logistics warehouses, manufacturing lines, etc. These traveling bogies move autonomously and transport articles along a pre-set route. A servo motor is used to drive the traveling bogie, and the servo motor plays an important role in achieving high-precision positioning and speed control. The servo motor is controlled by a servo driver. By supplying an appropriate current and voltage to the servo motor by the servo driver, the movement of the automated guided vehicle becomes possible. Further, based on an external control signal, the servo driver adjusts the rotation speed and torque of the servo motor to precisely control the operation of the traveling bogie.

[0003] For example, Patent Document 1 discloses an automated trolley capable of high-precision positioning control. In the following paragraph, reference numerals in Patent Document 1 are shown in parentheses. The trolley (3) of Patent Document 1 has auxiliary wheels (30) and drive wheels (31) for moving on a running rail (25). The drive wheels (31) are coupled to a servo motor (34) via a shaft and a gearbox (32), and are driven and controlled by this servo motor (34). An electromagnetic brake (33) is provided between the servo motor (34) and the gearbox (32) to stop the rotation of the drive wheels (31). The servo motor (34) is equipped with a tachogenerator (35) for detecting its rotational speed and a pulse encoder (36) for detecting the distance traveled, and forms a speed control loop and a position control loop with the position and speed control unit (1a), respectively. The position and speed control unit (1a) receives a stop position command signal from the higher-level controller (10), moves the trolley (3) at a corresponding speed, and drives the servo motor (34) so ​​that the trolley (3) stops at a predetermined horizontal position. In other words, the trolley (3) is equipped with the position and speed control unit (1a) and the higher-level controller (10) as servo drivers for controlling the servo motor. [Prior art documents] [Patent Documents]

[0004] Japanese Patent Application Publication No. 05-080843 [Overview of the project] [Problems that the invention aims to solve]

[0005] The trolley described in Patent Document 1 is equipped with a servo driver (position and speed control unit, higher-level controller) for controlling a servo motor. Generally, the servo driver is fixed to the trolley via a metal bracket of the housing structure. Figure 8 illustrates the bracket portion of the housing structure in a configuration where the housing structure of the servo driver is mounted and fixed to the trolley. As shown in Figure 8, the bracket 1 is made of a bent metal plate and comprises a bottom plate portion 2 that is placed and fixed on the mounting surface of the trolley, a rising portion 3 that extends upward from the bottom plate portion 2, and a support plate portion 4 that extends substantially horizontally from the upper end of the rising portion 3 and supports the servo driver. A mountain-fold bent portion 5 is formed between the rising portion 3 and the support plate portion 4. Since the servo driver also functions as a power source, it is often heavy, and the load on the support plate portion 4 of the bracket 1 is large. Furthermore, vibrations occur when the trolley is in motion, and these vibrations concentrate stress on the edge of the bent portion 5 of the bracket 1. Based on experience, it is known that, for example, metal fatigue from long-term use can easily cause cracks 6 to form on the edge of the bent portion 5, as shown in Figure 8. The occurrence of these cracks 6 reduces the support strength of the servo driver, requiring replacement or repair of the servo driver's housing structure to ensure safety. In other words, the problem with conventional housing structures is their low durability against repeated stress.

[0006] The present invention was made to solve the above problems, and its objective is to provide a servo driver housing structure with higher durability, and a trolley equipped with the housing structure. [Means for solving the problem]

[0007] (Composition 1) One embodiment of the present invention is a housing structure for a servo driver mounted on a trolley, A housing that houses the control device and has a bottom wall and a perimeter wall, A bracket made of a bent metal plate, provided on the bottom wall of the housing, for fixing the housing to the trolley, Equipped with, The aforementioned bracket is A bottom plate portion having a fixing portion that is placed on and fixed to the mounting surface of the aforementioned trolley, A rising portion extending upward from the bottom plate portion, It comprises a support plate portion that extends substantially horizontally from the upper end of the rising portion, is connected to the bottom wall, and supports the housing, A curved notch is formed at the edge of the folded portion between the rising portion and the support plate portion.

[0008] According to the housing structure of the present invention, by forming a curved notch at the edge of the mountain-folded portion between the rising portion and the support plate portion, which are the most prone to cracking in conventional housing structure brackets, repeated stress caused by vibrations of the trolley is dispersed instead of concentrating at a single point, and the occurrence of cracks due to metal fatigue can be effectively suppressed. Therefore, the housing structure of the present invention can improve its durability.

[0009] (Configuration 2) A further embodiment of the present invention is a housing structure in which, in the housing structure of configuration 1, the notch is formed to extend to both the rising portion and the support plate portion.

[0010] (Composition 3) A further embodiment of the present invention is a housing structure of configuration 2, characterized in that the inner surface of the notch has an arc shape in plan view.

[0011] (Composition 4) A further embodiment of the present invention is a housing structure of configuration 3, characterized in that the central angle of the arc of the notch is 180 degrees or more.

[0012] (Composition 5) In a further form of the housing structure of the present invention, in the housing structure of Configuration 4, the bottom wall has a rectangular shape in plan view, and the notch portions are provided at four corners of the bottom wall.

[0013] (Configuration 6) A traveling bogie according to one form of the present invention is a traveling bogie, a bogie body, a plurality of wheels pivotally supported on the bogie body, a servo motor that drives the plurality of wheels, a servo driver that controls the servo motor, and is provided with, the servo driver includes a housing structure according to any one of Configurations 1 to 5, and the housing structure is fixed to the bogie body via a bracket.

Advantages of the Invention

[0014] The housing structure of the present invention effectively suppresses the occurrence of cracks due to metal fatigue and improves durability by dispersing the repeated stress caused by the vibration of the traveling bogie without concentrating it at one point.

Brief Description of the Drawings

[0015] [Figure 1] Schematic plan view of a servo driver according to an embodiment of the present invention. [Figure 2] Schematic diagram showing a traveling bogie equipped with a servo driver according to an embodiment of the present invention. [Figure 3] Schematic diagram showing the overall configuration of the traveling bogie in FIG. 2. [Figure 4] Schematic plan view of the housing structure of the servo driver in FIG. 1. [Figure 5] Side view of the housing structure in FIG. 4. [Figure 6] Schematic perspective view showing a main part of the bracket of the housing structure in FIG. 4. [Figure 7] (a) Plan view and (b) side view of a main part of the bracket in FIG. 6. [Figure 8] Schematic diagram showing a bracket (with crack) of a housing structure of a conventional servo driver. [Modes for carrying out the invention]

[0016] One embodiment of the present invention will be described below with reference to the drawings. Note that the shapes in the drawings referenced in the following description are conceptual or schematic diagrams for illustrating preferred shapes, and the dimensional ratios, etc., do not necessarily correspond to actual dimensional ratios. In other words, the present invention is not limited to the dimensional ratios shown in the drawings.

[0017] Figure 1 is a schematic plan view illustrating a servo driver 11 according to one embodiment of the present invention. Figure 2 is a schematic diagram showing a mobile carriage 10 on which the servo driver 11 is mounted. Figure 3 is a block diagram showing the configuration of the mobile carriage 10. The servo driver 11 of this embodiment is mounted and fixed on the mounting surface of the carriage body of the mobile carriage 10, and is configured to control the operation of the mobile carriage 10, which can automatically move as an automated manual vehicle (AMR) or automated guided vehicle (AGV). Note that the mobile carriage 10 is not limited to logistics AGVs, etc., but may also be a heavy-duty special industrial vehicle.

[0018] More specifically, the trolley 10 comprises a trolley body 10a having a mounting surface (fixed surface), a plurality (four) of wheels 13 pivotally supported on the trolley body 10a, a servo motor 12 for driving each of the plurality of wheels 13, and a servo driver 11 for controlling the servo motors 12. As shown in Figure 2, the servo driver 11 is fixed to the mounting surface of the trolley body 10a via a fixing part 117. Also, as shown in Figure 3, the servo driver 11 controls the operation of the servo motors 12 by being electrically connected to the servo motors 12 corresponding to the four wheels 13 of the trolley 10. The servo driver 11 enables autonomous operation of the trolley 10 by individually controlling the amount of rotation, speed, turning direction, etc., of each wheel 13. The servo driver 11 may also control the trolley 10's movement using GPS location information, information from cameras and sensors.

[0019] The servo driver 11 includes a hollow housing structure 100 that houses a control device (electronic device). Figures 4 and 5 are schematic plan and side views showing the housing structure 100 of the servo driver 11 with the control device omitted. This housing structure 100 includes a housing 101 that houses the control device and has a bottom wall 102 and a periphery wall 103, and a bracket 110 for fixing the housing 101 to the bogie body 10a of the traveling bogie 10. In plan view, the housing 101 has a rectangular shape with vertical sides (up and down direction in Figure 4) and horizontal sides (left and right direction in Figure 4). The bracket 110 is made of a bent (bent) metal plate and is provided on the bottom wall 102 of the housing 101. In this embodiment, the bracket 110 is connected to two locations at both ends in the vertical direction of the bottom wall 102, which is rectangular in plan view, and extends outward in the vertical direction of the periphery wall 103. Furthermore, the bracket 110 extends along the entire side of the housing 101. As shown in Figure 5, the bracket 110 is bent in the height direction, so that the bottom wall 102 of the housing structure 100 of the servo driver 11 is positioned away from the mounting surface of the trolley 10. This prevents vibrations and shocks generated when the trolley 10 is running from being directly transmitted from the bottom wall 102 of the housing structure 100 to the internal control device.

[0020] Figure 6 is a schematic perspective view showing characteristic parts of the bracket 110. Figures 7(a) and 7(b) are its plan view and side view. The bracket 110 comprises a bottom plate portion 111 having a fixing portion 117 that is placed on and fixed to the mounting surface of the trolley 10, a rising portion 112 that extends upward from the bottom plate portion 111, and a support plate portion 113 that extends substantially horizontally from the upper end of the rising portion 112, is (integrally) connected to the bottom wall 102, and supports the housing 101. In this embodiment, the support plate portion 113 and the bottom wall 102 are integrally connected. A substantially right-angle valley fold portion 114 is formed between the bottom plate portion 111 and the rising portion 112. In addition, a substantially right-angle mountain fold portion 115 is formed between the rising portion 112 and the support plate portion 113. In other words, the support plate portion 113 is the part that directly receives the load of the housing 101 and the control device inside it, and is prone to bending and deforming around the mountain-folded portion 115 due to vibrations during driving, etc. Therefore, the mountain-folded portion 115 is more susceptible to repeated stress than other parts (for example, the valley-folded portion 114).

[0021] Furthermore, a curved notch 116 is formed at the lateral edge of the mountain-fold portion 115. In other words, the sharp corners where stress tends to concentrate are removed from the mountain-fold portion 115. The notch 116 is formed to extend to both the rising portion 112 and the support plate portion 113. In this embodiment, the notch 116 also extends to a portion of the thickness of the peripheral wall 103. The notch 116 has a roughly semicircular shape, and its inner surface extends in a curved manner. The inner surface of the notch 116 has a circular arc shape or a C-shape in plan view. In this embodiment, the central angle of the arc of the notch 116 is 180 degrees or more. In other words, because the edges of the folded portion 115 of the bracket 110 are curved in an arc shape by the notches 116, it is possible to distribute the repeated stress caused by vibrations of the trolley 10 without concentrating it in a specific location. These notches 116 are formed at both ends of the bracket 110 in the lateral direction and are provided at each of the four corners of the bottom wall 102 of the housing structure 100.

[0022] The trolley 10 of this embodiment and a trolley with the same configuration but without the notch 116 were tested and run for an extended period of time. While the conventional trolley developed cracks as shown in Figure 8, it was confirmed that no cracks developed in the trolley 10 of this embodiment under the same conditions.

[0023] Therefore, the housing structure 100 of this embodiment effectively suppresses the occurrence of cracks due to metal fatigue by distributing the repeated stress caused by vibrations of the trolley 10 instead of concentrating it, thereby enabling it to exhibit higher durability than conventional structures.

[0024] The present invention is not limited to the embodiments described above, and various embodiments and modifications are possible. Modifications of the present invention will be described below.

[0025] (1) The housing structure and trolley of the present invention are not limited to the configuration of the above embodiment. In the above embodiment, one servo driver was described as being mounted on the trolley, but multiple servo drivers may be mounted on the trolley.

[0026] (2) The housing structure and trolley of the present invention are not limited to the configuration of the above embodiments. In the above embodiments, the notch in the housing structure is semicircular in shape, but the present invention is not limited thereto. The notch is not limited to a semicircular shape and may be an oval, elliptical, or randomly curved shape.

[0027] The present invention is not limited to the embodiments or modifications described above, and can be implemented in various forms as long as they fall within the technical scope of the present invention. That is, within the technical scope of the present invention, some of the configurations of this embodiment may be omitted or modified, or other configurations may be added. [Explanation of Symbols]

[0028] 10. Running bogie 10a Trolley body 11 Servo Driver 12 servo motors 13 wheels 100 Housing structure 101 Housing 102 Bottom wall 103 Peripheral wall 110 bracket 111 Bottom plate part 112 Rising section 113 Support plate part 114 Valley fold section 115 Folded part of a mountain fold 116 Notch 117 Fixed part

Claims

1. A housing structure for a servo driver mounted on a traction motor, A housing that houses the control device and has a bottom wall and a perimeter wall, A bracket made of a bent metal plate, provided on the bottom wall of the housing, for fixing the housing to the trolley, Equipped with, The aforementioned bracket is A bottom plate portion having a fixing portion that is placed on and fixed to the mounting surface of the aforementioned trolley, A rising portion extending upward from the bottom plate portion, It comprises a support plate portion that extends substantially horizontally from the upper end of the rising portion, is connected to the bottom wall, and supports the housing, The housing structure is characterized in that a curved notch is formed at the edge of the mountain-folded portion between the rising portion and the support plate portion.

2. The housing structure according to claim 1, characterized in that the notch is formed to extend to both the rising portion and the support plate portion.

3. The housing structure according to claim 2, characterized in that the inner surface of the notch has an arc shape in plan view.

4. The housing structure according to claim 3, characterized in that the central angle of the arc of the notched portion is 180 degrees or more.

5. The housing structure according to claim 4, characterized in that the bottom wall has a rectangular shape in plan view, and the notches are provided at the four corners of the bottom wall.

6. It is a trolley, The trolley body and Multiple wheels are axle-supported on the aforementioned bogie body, A servo motor that drives the aforementioned plurality of wheels, The servo motor is controlled by a servo driver, The servo driver comprises the housing structure described in any one of claims 1 to 5. A trolley characterized in that the housing structure is fixed to the trolley body via a bracket.

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