JP7332196B2 - Parts management cabinet for high-sensitivity centralized weighing and counting - Google Patents

Description

Field of the Invention The present invention belongs to the technical field of warehouse management system, and relates to an intelligent parts management cabinet, especially to a stacking installation, centralized sensitive weighing parts management cabinet.

In the parts management of the high-tech intelligent manufacturing and maintenance industry, when relying on manual labor, there are disadvantages such as not being able to supply parts in time, and the quantity statistics are not accurate. Therefore, we devised this intelligent parts management technology.

Patent Literature 1 discloses a kind of parts management device. It includes a pull-out cabinet containing a box-type frame and a plurality of drawers, each of which is provided with a number of parts storage units, each with a locking mechanism. A beneficial effect of the present invention is that by using a computer management system, the necessary parts can be found quickly, avoiding the time lag of relying on human labor. However, since there is no parts weighing unit installed, the number of parts in the drawer cannot be measured, and parts cannot be replenished in real time.

Patent Literature 2 discloses an intelligent parts management cabinet with quantity display. It includes multiple drawers with cabinets, control systems and metering capabilities. Each parts drawer is fixed on the top of the cabinet with an electronic lock, and a load cell is installed at the bottom of the parts drawer, which consists of an intelligent parts management cabinet that identifies and manages the recipient of the parts. The number of parts can be displayed in real time, data can be aggregated and reported via the Internet, and detailed management of parts can be realized in real time. The problem with this cabinet, however, is that each drawer has a load cell, which adds to the cost of the system and increases the weighing process and measurement uncertainty.

Chinese Patent "Parts Management Device, 201610303077.5" Chinese Patent "Intelligent Parts Management Cabinet and Delivery System with Quantity Display, 201710769328.3"

The present invention proposes a parts management cabinet for high-sensitivity centralized weighing and counting, one weighing unit weighs several parts drawers on the upper level, and makes a count display according to the weight of the parts. Adopting a support mechanism overcomes the problem that the weight of the cabinet affects the measuring range of the load cell, greatly improving the weighing sensitivity.

The above component management cabinet for sensitive centralized weighing and counting includes a cabinet body, a body bottom frame, a support mechanism and a control survey module. The cabinet body is installed on the bottom frame, several stacked parts storage drawers are installed inside the body, and the weighing unit is installed on the cabinet bottom frame to measure the weight of the entire parts management cabinet in real time. ;The above support mechanism applies a constant upward support force to the bottom frame of the cabinet, and the value of the support force is less than the weight of the cabinet frame without parts;The control and measurement module controls the opening of the drawer. , based on the load cell parameters, calculate and display the quantity of parts in the parts management cabinet.

The weighing unit in the above parts management cabinet for high-sensitivity centralized weighing and counting includes a plurality of load cells installed on the bottom frame of the cabinet, the fixed ends of the load cells are fixed with adjusters, and the movable ends are bolted to the bottom of the body. Connected to the top of the steel plate of the frame. The weight of the parts management cabinet is applied through the steel plate to the load cell to measure the weight of the parts management cabinet.

In the above sensitive centralized weighing and counting parts management cabinet, a kind of support mechanism is a plurality of piston units installed under the cabinet bottom frame, the piston units support the cylinder and the upper and lower slide rods in the cylinder include. An upper chamber and an intermediate chamber are formed respectively between the upper end and the central portion of the rod and the cylinder body of the cylinder. Between the upper chamber and the middle chamber are connected by several orifices. A check valve is installed at the upper end of the cylinder and serves as a pressure medium to the upper chamber.

A seal is installed between the cylinder and the rod in the parts management cabinet for the above sensitive centralized weighing and counting.

In the above high-sensitivity centralized weighing and counting parts management cabinet, a kind of support mechanism is the lever counterweight unit, the fulcrum of the lever is installed on the lever base, and the short lever arm end exerts an upward force on the cabinet body. give. The long lever arm end of the lever is rigidly connected to the counterweight.

In the above sensitive centralized weighing and weighing parts management cabinet, a plurality of lever counterweight units are installed under the parts management cabinet, and the fulcrum of each lever is fixed on a height-adjustable lever base. The action point of the short lever arm end is set on the steel plate on the outer circumference of the bottom frame of the main body, and the long lever arm end of the lever is firmly connected to the same counterweight through the weight.

The lever torque ratio of the parts management cabinet for high-sensitivity centralized weighing and counting is 10-20:1.

In the above component management cabinet for sensitive centralized weighing and counting, the control measurement module includes an upper computer, a user authentication unit and a lower computer, the upper computer is connected to the user authentication unit, the lower computer is connected with the weighing unit Connected to electronic locks installed in drawers. The lower computer controls the opening of the drawers and uploads part quantity data to the upper computer.

A square washer is installed between the steel plate and the load cell in the above parts management cabinet for high-sensitivity centralized weighing and counting.

In the parts management cabinet for high-sensitivity centralized weighing and counting, a plurality of load cells are installed at the four corners of the parts management cabinet, the load cells are beam-type load cells, and strain gauges are attached to the load cell bodies.

The present invention changes the measurement method of the traditional parts cabinet, which weighs a single part with independent configuration load cells, and consists of multiple drawers, suitable for multiple parts, unified weighing, intelligent weighing Suggest an administration cabinet. Only one set (four) load cells are installed at the bottom of the cabinet, using software algorithms to complete the weighing measurement of many kinds of parts in the upper multi-layer drawers, and the parts in the drawers in real time can be calculated. However, only one drawer can be opened at a time. A complete set of cabinets is equipped with only one set of load cells, which can complete the measurement and control of many kinds of parts, and the hardware configuration cost per unit is lower than the traditional weighing control system. low, system cost-effective.

The load cell used in the present invention is required to measure the weight of the entire cabinet. The weight includes not only the weight of the components, but also the weight of the cabinet itself. Due to structural strength requirements, the dead weight of the cabinet often dominates the effective measurement range. In general, a load cell with a wide measuring range is required to meet the measuring range requirements. However, the wider the measurement range of the load cell, the larger the minimum detectable weight, the lower the sensitivity, and the lower the measurement accuracy. In order to ensure the measurement accuracy and effectively reduce the waste of the measurement range, the present invention adds a set of independent support mechanisms at the bottom of the cabinet, which provides a constant upward direction to the cabinet body while measuring. It can generate bearing force, greatly reduce the self-weight of the cabinet, and reduce the load range of the load cell, and at the same time can effectively reduce the measurement range of the load cell without affecting the measurement accuracy. The support mechanism has two structural forms: a piston-type support mechanism and a lever-counterweight support mechanism.

The piston-type support mechanism adopted in the present invention has a simple structure and is easy to install. I can handle it. Under the quasi-static conditions of loading and unloading parts, this device effectively exerts a constant bearing force and guarantees measurement accuracy.

The lever counterweight support mechanism used in the present invention consists of four fixed fulcrums, four lever lever arms and a counterweight. The ends of the short lever arms of the four levers are supported upward on the lower surface of the cabinet bottom frame, and the ends of the long lever arms are connected to the counterweight via weights. By increasing the leverage ratio, a smaller counterweight can be used, providing greater constant force support and offsetting the weight of the cabinet itself. At the same time, multiple levers share the same counterweight, the structure is simple, it is convenient to adjust the counterweight according to the range of cabinets, and the condition of constant bearing capacity for cabinets of various specifications can meet.

The parts cabinet of the present invention employs a lever-arm type load cell with four independent adjusters to support the parts cabinet with gas springs and has the function of detecting weight changes of parts. It has high precision measurement data, simple structure, easy installation, testing and maintenance.

1 is a structural schematic diagram of the original stacking parts management cabinet of the present invention; FIG. FIG. 4 is a schematic diagram of the internal structure of the original stacking parts management cabinet of the present invention; 3 is a configuration diagram of a control measurement module of the present invention; FIG. 1 is a configuration principle diagram of a lower computer of the present invention; FIG. 1 is an installation diagram of a load cell of the present invention; FIG. 1 is a principle diagram of a load cell of the present invention; FIG. It is a principle diagram of a parts management cabinet provided with the support mechanism of the present invention. 1 is a principle diagram of a parts management cabinet that employs a piston-type support mechanism; FIG. (Example 1) It is a structural diagram of a piston unit. (Example 1) FIG. 4 is a structural diagram of a count weight support mechanism and a weighing unit; (Example 2) FIG. 11 is a bird's-eye view of FIG. 10; 11 is a front view of FIG. 10; FIG.

As shown in Figure 1-3, the original multi-layer drawer centralized weighing parts management cabinet invented by the company includes a cabinet body 5, a cabinet bottom frame 3, and a control measurement module 1. A cabinet 5 is installed on a cabinet bottom frame 3, and a plurality of drawers 2 for storing parts are provided vertically stacked in the cabinet 5, and the parts are sorted and installed in different drawers. A set of load cells is installed on the cabinet bottom frame 3 to measure the weight of the entire parts management cabinet in real time. The parts drawer is secured to cabinet 5 by an electronic lock. With user login, the drawers are automatically opened with an electronic locking function by the user authentication unit.

The control and measurement module 1 includes an upper computer, a user authentication unit and several lower computers, each lower computer being installed in an installed parts management cabinet. The upper computer can connect up to 63 sets of lower computers via the RS485 bus, and one upper computer can manage up to 63 sets of parts cabinets. The upper computer is a human-computer interaction interface, and it is recommended to use a tablet. The upper computer runs dedicated control software. The home screen of the software displays the product name, specifications, inventory count, and low-stock warning amount of parts stored in multiple cabinets and multi-level drawers, with color indicating the open/close status of the drawer.

A host computer is connected to the user authentication unit via a COM interface (or USB interface), reads the user's ID information, and performs verification and login. The user authentication unit is composed of one or more combinations of a contactless IC card recognition module, a fingerprint recognition module, a face recognition module, and an iris recognition module. It is easy to use by adopting multiple recognition methods, and adapts to various usage environments and habits.

When a part is put in or taken out, the lower computer detects the operation of the cabinet button and releases the corresponding electronic lock of the drawer to complete the opening of the drawer. The lower computer is connected to the weighing unit to complete the weight measurement and the weighing and display of the drawer of the predetermined parts, and upload the result data to the upper computer. After completing loading and unloading of parts, the user can manually close the drawer directly.

In Figure 4, the lower computer is mainly composed of MCU, RS485 transceiver, lock control circuit, metering circuit and control board. The MCU of the lower computer sends and receives commands and data through the power supply unit of the higher computer via the RS485 transceiver and RS485 bus. A lock control circuit interfaces with a plurality of electronic locks to open drawers and monitor their status. The weight change of the cabinet is measured by the load cell circuit monitor, and the measurement data is uploaded to the MCU in real time. The control panel is used to display real-time quantity information for cabinet numbers and parts.

The host computer has functions such as editing of parts information and data construction, inventory display, inventory warning, parts access record search, user management, and network shared data. A parts database can be created through an input interface. Inventory data uploaded by the subordinate computer is collected and displayed in real time. Part access statements are automatically generated and the parts database is updated at the same time. It can be connected to the network by cable or Wi-fi to share data information and realize remote management.

As a method of implementation, the control and measurement module 1 includes a power supply unit, thereby supplying power to a plurality of subordinate computer systems upon user login. After completing the access operation, it will be powered off and logged off. At the same time, it serves the purpose of saving system power in the non-login state.

As shown in FIGS. 5 and 6, the weighing unit includes four load cells 6 mounted on the cabinet bottom frame 3 . Four load cells 6 are fixed to the four corners of the cabinet bottom frame with two bolts each. The ends of the bottom frame are fixed to the ground 12 by one adjuster 4 each. The four adjusters are adjusted to be flat, and the weight of the cabinet is measured by the electrical signals output by the four load cells 6.

The load cell of the present invention employs a four-wire beam load cell, two excitation power supply input lines, and two strain signal output lines. The electrical signals output by the four load cells are connected in parallel and converted by an amplification and AD conversion circuit. Based on the weight data collected via the AD conversion circuit, the weight difference before and after the part is taken in and out can be calculated. A part quantity change value can be calculated by comparing with a predetermined specific weight of a single part. This value is positive if the part is put in, and negative if the part is taken out. This value is displayed in real time on the control panel, and when the drawer is closed, the calculated value is uploaded to the host computer.

As shown in Fig. 7, in order to improve the measurement accuracy and the resolution of light and small parts, we devised a parts management cabinet structure with a support mechanism. In the example of the original multi-drawer centralized weighing parts management cabinet shown in Figure 1-6, parts are placed in drawer 2, drawer 2 is installed in cabinet 5, and cabinet 5 is installed on cabinet bottom frame 3 (Drawer 2, cabinet 5 and cabinet bottom frame 3 are collectively referred to herein as the frame). In order to provide strength, the weight of the frame containing the parts may be greater than the total weight of the parts, which may put pressure on the effective measurement range of the load cell 6 . Generally, in order to ensure the measurement range of the parts, it is necessary to select a load cell with a wide measurement range, and the weight of the entire parts cabinet must be within that range. At the same time, the load cell must have some degree of measurement accuracy and resolution to detect minute changes in lightweight parts. Therefore, the load cell must satisfy both wide range and high resolution at the same time, which creates a contradiction.

Assuming that the weight of the parts is 50kg and the weight of the frame is 50kg, it is necessary to select a C3 class load cell that satisfies the 100kg range. The load cell accuracy is 0.033% of the full range. The weighing uncertainty is 33g, which means that a parts cabinet with a C3 class load cell can detect a part weight of 33g, and parts weighing less than 33g cannot be detected or counted accurately.

If a support mechanism is installed below the cabinet, a constant upward support force of 40 kg is used to offset most of the dead weight of the cabinet. The maximum weight on the load cell will be 60kg, so you can switch to a C3 class load cell with a range of 60kg and a weighing uncertainty of 20g. In other words, the detectable part weight of a parts cabinet equipped with a C3 class load cell is 20g, which improves detection accuracy.

In order to offset or reduce the weight of the frame, the support mechanism 20 requires a certain amount of support. That is, even if the weight of the parts in the parts cabinet changes, the supporting capacity of the parts cabinet remains constant. To ensure the stability of the equipment, the supporting capacity should generally be less than the weight of the empty parts cabinet, the difference being maintained at about 10 kg.

8 and 9 are structural diagrams of a parts management cabinet employing a piston-type support mechanism in the first embodiment. In FIG. 8, four load cells 6 are installed under the cabinet bottom frame 3 and each load cell 6 is supported on the ground by adjusters 4 . A piston-type gas spring is provided at the central position on both sides of the cabinet bottom frame 3 to support the cabinet body with a certain force.

The piston unit includes a cylinder 31 , a rod 32 that can slide up and down within the cylinder 31 and a seal 38 . The upper end 33 of the rod 32 has a stepped structure, thicker at the upper end and thinner at the middle; The middle part outer layer of the rod 32 and the cylinder body of the cylinder 31 form the middle chamber 35, the upper end 33 of the rod 32 is provided with several orifices 36 connecting the upper chamber 34 and the middle chamber 35, The chamber 34 and the intermediate chamber 35 are filled with a gas or gas-liquid mixture pressure medium. As the rod 32 moves, pressure medium can flow in the two empty chambers.

A check valve 37 is provided at the upper end of the cylinder 31 . After filling the upper chamber 34 with a gas or gas-liquid mixture at the set pressure, the check valve 37 is immediately sealed. A seal 38 is provided between the cylinder 31 and the rod 32 to provide a movable sealing of the pressure medium within the cylinder 31 . After pressure filling, the rod 32 is pushed out and stays at a certain position in the closed cylinder 31, the thrust to the outside thereof being constant. In use, the top of the cylinder 31 rests on the top of the cabinet bottom frame 3 and the bottom of the rod 32 rests on the ground.

In order to explain the principle of supporting the piston with a constant force, the following explanation will be given.

Assuming that the rod 32 as a whole extends out of the cylinder after the gas and liquid flow into the cylinder 31, if C is the gas-liquid volume in the cylinder, P is the pressure, and A is the cross-sectional area of the rod, then the thrust of the rod is F = AP.

Assuming that the rod is pushed into the closed cylinder by a distance s, the thrust of the rod is:

Taking the derivative of the above equation, the thrust rate of change is:

For P = 1 MPa, s = 50 mm, rod diameter 10 mm, cylinder length 200 mm, inner diameter 18 mm, that is

A = ^78.54mm2 , C = ^5.089x104mm3 . According to the formula, the thrust change rate is as follows.

The parts weighing process is quasi-static and the piston essentially does not expand or contract. When loading and unloading parts normally, the total deformation of the load cell and the cabinet body shall not exceed 0.1mm. Therefore, it is considered that the thrust change does not exceed 0.0142N, or approximately 1.4g. Since the change in thrust is small in this way, the bearing force can be considered constant and does not affect the measurement.

Figures 10-12 show the principle of operation when the support mechanism 20 of the second embodiment is a lever counterweight unit, which consists of four fixed fulcrums, four lever lever arms and one counterweight mount. The short lever arm ends of the four levers are supported upwards on the bottom of the cabinet, and the long lever arm ends are firmly connected to the counterweight. The weight of the counterweight is translated into a constant upward bearing force at the ends of the short lever arms of the four levers, offsetting most of the weight of the cabinet. As the part is moved in and out, the weight of the counterweight does not change, so the support force of the lever on the bottom frame of the cabinet remains constant.

10, lever 41 includes fulcrum 42, short lever arm end 43, and long lever arm end 44. In FIG. The fulcrum 42 of the lever 41 is mounted on a height-adjustable lever base 46 with a short lever arm end 43 bearing against the cabinet bottom frame 3 under the steel plate 7 and exerting an upward force on the cabinet bottom frame 3. and the long lever arm end 44 of lever 41 is rigidly connected to a counterweight 45 .

As a further embodiment, as shown in FIG. 11, the point of action of the short lever arm end 43 is set on the outer steel plate 7 of the cabinet bottom frame 3 and the long lever arm end 44 of the lever 41 carries two weights 47. Firmly connected with the counterweight 45 via. The cross section of the lever 41 is rectangular to increase the bending moment. A count weight 45 is installed in the center of the cabinet bottom frame 3 , a center screw 48 is provided in the center of the count weight, and the count weight 45 is fixed to the center screw 48 . The two weights 47 are of hollow construction and pass through on the center screw 48, the bottom of the upper weight and the top of the lower weight are provided with corresponding grooves, and the long lever arm ends 44 of the four levers 41 are each 4 It is crimped into the groove from one angle and firmly connected with the counterweight 45.

The counterweight 45 can be easily exchanged for different counterweight requirements. Furthermore, the torque ratio of the lever 41 was set to 10-20:1. In this way, a large counterweight can be realized with a small counterweight, and the overall weight of the frame can be almost offset. Also, when sampling parts, the whole can be supported with a constant force. At the same time, since the fulcrum 42 of each lever 41 is fixed to the height-adjustable lever base 46, it is easy to adapt to the height of the parts cabinet adjuster 4.

As a further example, the four lever bases 46 can be installed on a bottom plate with the same frame to provide stable support and ease of installation.

The main functions and operating procedures of the parts management cabinet are described in detail below.

1. User authentication and electronic bookkeeping.

Boot the device's host computer and enter the system user interface. The user authentication unit first recognizes the user's ID and confirms the operation authority to put in and take out parts. Then, the history of taking in and out the parts after that is recorded and saved.

2、Creating a parts list

In the user interface, assign the appropriate part drawer according to incoming part size and enter information such as part name, specification, unit, replenishment reminder quantity, and remarks.

3, parts rating

Pressing the button corresponding to a part specification on the user interface causes the corresponding parts drawer to enter initialization mode, weigh and store the weight of the empty drawer. Enter and confirm the quantity of parts to be received in the user interface, and the drawer will automatically open. After placing this quantity of parts in the drawer, closing the drawer completes the initialization.

4, warehousing and delivery of parts

Pressing the green button on the cabinet automatically opens the corresponding parts drawer, the monitor immediately displays the quantity of existing parts, and the parts can be taken in and out directly. Each time you remove a part, the number of parts on your monitor decreases by one. Adding a part increases the number of parts on the monitor by one. Manually closing the parts drawer completes the loading/unloading operation.

5、Inventory confirmation and remote data management

Users can easily query the quantity of existing parts in the cabinet from the list on the user interface, and at the same time share the parts list through the local area network for easy remote data collection and analysis.

6, inventory shortage alarm

If the quantity of parts in the drawer is less than the preset quantity, the user interface will display a message to replenish this specification part.

The present invention forms an intelligent parts management system or intelligent parts management warehouse based on multiple high-sensitivity centralized weighing and counting parts management cabinets, which can automatically manage multiple parts in a large-scale production line, run out of inventory alarm, inventory statistics, It also has functions such as automatic bookkeeping, realizing unmanned warehouses, centralizing server terminal generalization and data management, and realizing modern and sophisticated management of parts.

1 control measurement module 2 drawer 3 cabinet bottom frame 4 adjuster 5 cabinet body 6 load cell 7 steel plate 8 bolt 9 angle washer 10 movable end 11 fixed end 12 ground 15 cable output end 20 support mechanism 31 cylinder 32 rod 33 upper end 34 upper chamber 35 middle Chamber 36 Orifice 37 Check Valve 38 Seal 39 Piston Base 41 Lever 42 Fulcrum 43 Short Lever Arm 44 Long Lever Arm 45 Counterweight 46 Lever Base 47 Weight 48 Center Screw

Claims (2)

It is a kind of component management cabinet for high-sensitivity centralized weighing and counting, and has the following features. A plurality of lever counterweight units are installed under the parts management cabinet, and the fulcrum (42) of each lever (41) is fixed on a height-adjustable lever base (46). The action point of the short lever arm end (43) is installed on the steel plate (7) around the bottom frame (3) of the cabinet body, and the long lever arm end (44) of the lever (41) is connected to the same counter through the weight (47). The weight and (45) are rigidly connected. The parts management cabinet for sensitive centralized weighing and counting according to claim 1 has the following features. The torque ratio of the lever (41) is 10-20:1.

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