METHOD FOR DETERMINING A FORCE WHEN INSERTS A BATTERY MODULE INTO A BATTERY HOUSING

Description

Technical field

[0001] The present invention relates to a method for determining at least one force when inserting a battery module into the battery housing. State of the art

[0002] When assembling battery modules into a battery housing, the modules are inserted into a battery frame and mounted. The housing is then closed, usually by screwing or welding a lid on. The battery modules comprise an array of individual battery cells. During operation, heat is generated in the cells, which must be dissipated, primarily through the battery housing. To achieve this, a thermal paste is applied to the battery frame before the modules are mounted. This paste ensures and enhances thermal conductivity between the modules and the housing. The modules are then pressed onto the frame, partially displacing the thermal paste, and finally screwed to the frame.During assembly, high forces are generated when pressing and screwing the battery module into place. These forces can currently be measured using a pressure-sensitive film, such as a Fuji Film film according to US 6,742,472 B1. However, the pressure-sensitive film only measures the total forces during pressing or screwing the battery module. To evaluate the measured forces, a user must remove the battery module from the battery housing and analyze the intensity of the discoloration on each pressure-sensitive film. The discoloration corresponds to the total forces exerted during pressing and screwing the battery module. Therefore, the pressure-sensitive films cannot be used to measure the force over time during pressing or screwing the battery modules.The battery module is then reinserted into the battery housing and screwed in place based on the total forces determined using the pressure-measuring film, so that the internal stresses in the battery cells of the battery module and the battery frame are reduced to a minimum, thus ensuring a long service life for the battery modules.

[0003] DE 102019 101 403 describes a method for measuring at least one section of a battery module and one section of the battery housing by determining the size and shape of a gap that results in the intended installation position of the battery module. The quantity of thermal conductivity is then determined based on the measured size and shape of the gap and subsequently applied to the battery housing. This ensures that the optimal amount of thermal conductivity is present when the battery module is inserted into the battery housing, thus reducing the forces involved in pressing and screwing the battery module into the housing.

[0004] Since these conventional methods for evaluating the total forces during the pressing and screwing of the battery module onto the battery frame of the battery housing are already very time-consuming in the production process, the forces during the final screwing of the cover onto the battery housing are also not currently considered.

[0005] DE 10 2012 207 999 A1 discloses a covering film for a galvanic cell. The covering film has at least one force sensor for detecting a state of strain in the covering film.

[0006] CN 109 449 519 A discloses a device for detecting lithium-ion batteries. Description of the invention

[0007] One objective of the invention is therefore to demonstrate an improved force measurement during an assembly process of battery modules in a battery housing, using the simplest possible means in terms of construction.

[0008] The problem is solved by the subject matter of the independent claim. Advantageous embodiments of the invention are specified in the dependent claims, the description, and the accompanying figures.

[0009] One aspect of the disclosure relates to a force-measuring module for detecting a force when a battery module is inserted into a battery housing, the housing having essentially the same external dimensions and shape as the battery module; and at least one force sensor arranged and configured in the housing to detect a force when the housing is inserted into the battery housing. When the housing is inserted into the battery housing, the force-measuring module is, for example, pressed into a battery compartment of the battery housing. This generates forces which are measured by the force sensor. For example, the force sensor can also measure a time-dependent force profile during the pressing process.The force measuring module according to the present patent application is used as a kind of substitute for the actual battery module to be inserted during an initial pressing and screwing operation, so that the forces occurring, and in particular their temporal profile, can be measured more accurately by the force sensor compared to conventional methods. Afterwards, the force measuring module can be easily removed from the battery housing and the measured forces can be easily read out and used in the production process. The use of a pressure-sensitive film is also no longer necessary according to the present method.After removing the force measuring module, the corresponding battery module can be inserted into the battery housing and, taking into account the measured forces, finally pressed and screwed in place using the force measuring module, thereby minimizing the internal stresses occurring within the battery cells in the respective battery module and within the battery housing.

[0010] The force measurement module comprises a cover, a central section, and a base. It also includes a measuring amplifier. The amplifier can be connected to a data processing unit via a wireless interface and allows for increased measurement accuracy of the force sensors, thus enabling better analysis of the measured values. For example, the amplifier can be located in the central section of the force measurement module. The central section can also include a rocker switch for turning the module on and off, a replaceable battery for power, and heat exchangers for heat dissipation. The cover protects the force measurement module from damage and contamination.The force measurement module is preferably designed as a self-contained system with its own energy supply and measurement system, so that continuous use of the force measurement module within the production process is possible.

[0011] Since the shapes and external dimensions of the individual battery modules vary within certain tolerance limits, it is further proposed to measure the shape and external dimensions of each battery module to be used and to adapt the shape and external dimensions of the force-measuring module housing to the shape and external dimensions of the respective battery module. For this purpose, rails are preferably arranged in the base, lid, and / or side walls of the force-measuring module, which can be connected to corresponding brackets and fixings on the side walls in the base and / or lid of the force-measuring module, thus enabling flexible adaptation to different shapes and external dimensions of the force-measuring module housing. The adjustment of the shape and external dimensions of the housing can be made manually by an operator by locking the brackets onto the respective rail or...This is done by electric actuators using an electric control system.

[0012] This ensures that the forces and force changes measured by the force measuring module accurately correspond to the forces and force changes that occur during the subsequent pressing or screwing of the associated battery module into the battery housing, or during the screwing of the cover onto the battery housing. Based on precise knowledge of the expected forces and force changes during pressing and screwing, the pressing and screwing forces of the associated battery module can be accurately predicted and applied. By applying only the necessary pressing and screwing forces when inserting the battery module, the internal stresses within the battery module and within the battery housing are reduced to a minimum, thus extending the battery's service life.

[0013] Several force sensors are arranged on the housing or within the force measuring module to measure the force at multiple points. To obtain precise measurements, the force sensors can be arranged so that the force measuring module is statically determinate. The resulting force can then be calculated via the center of gravity of the force measuring module. To avoid measurement errors, the force sensors can, for example, be arranged in a triangle that covers as much of the area as possible.

[0014] Alternatively, the force sensors can be arranged at force-sensitive points within the force module. For example, it is envisaged that the force sensors are arranged on the opposite side of the force measuring module housing from the screw bosses or screw channels into which the screws are screwed. During tightening, concentrated stresses form around the screw bosses or screw channels, which are transferred to the battery module or battery housing and generate internal stresses. It is also envisaged, within the scope of the present patent application, to arrange force sensors in those areas of the force measuring module where the greatest internal stresses are expected during pressing and screwing.

[0015] The force measuring module also includes at least one heat exchanger, for example a fan, which dissipates the heat generated during operation. This ensures that the temperature of the force measuring module does not affect the force sensor measurements and is adjustable to the temperature during the pressing and screwing of the battery module, so that no additional temperature-induced forces occur during the measurement by the force measuring module compared to the pressing and screwing of the associated battery module.

[0016] Furthermore, the force sensor can be positioned in a base plate and inserted into the battery housing. Multiple force sensors can be arranged in the base plate. The force sensor can be attached to the base plate using a shoulder screw. The force sensor can also be fixed to the central part of the force measuring module. Additionally, the force sensor can have a hardened surface. During force measurement, the weight of the force sensor and / or the force measuring module is not taken into account, so only the forces and force changes actually occurring due to pressing and / or screwing are measured.

[0017] According to a preferred example of the disclosure, the force measuring module comprises at least two force sensors arranged spatially distributed within the housing and each configured to detect the force when the housing is inserted into the battery housing. By arranging multiple force sensors on the housing, the force can be measured at several points. Subsequent evaluations can either assess the forces and force changes with respect to the respective positions of the force sensors or, using mathematical functions, assess them with respect to specific areas of the force measuring module, for example, by averaging the forces at three points over the area between the three points.

[0018] To ensure perfect parallelism between the base and the central section, both can be milled flat after assembly of the force measurement module. The contact surfaces between the sensors and the central section can be made of wear-resistant and stainless steel. Surfaces where the force measurement module is bolted can also be made of wear-resistant and stainless steel. For example, the cover of the force measurement module can be made of aluminum. To minimize the weight of the force measurement module, the steel can be designed with cutouts.

[0019] Furthermore, the housing has an arrangement configured to screw the force measuring module to the battery housing and / or to a cover, wherein the at least one force sensor is configured to detect a force on the force measuring module when screwing the force measuring module to the battery housing and / or the cover.

[0020] According to another preferred example of the disclosure, the force measuring module comprises a data processing unit configured to acquire and evaluate a force sensor signal from the at least one force sensor. The data processing unit can be connected to the measuring amplifier via a data network, for example, Ethernet. The force sensor signal can be acquired and evaluated by the data processing unit in real time. Likewise, the data processing unit can acquire and evaluate the force profile over time during the pressing or screwing of the force measuring module.

[0021] Furthermore, the force measuring module includes a wireless interface, specifically a WLAN interface, configured to transmit data from the force measuring module to another data processing device. This other data processing device could, for example, be an external computer operated by a user. The wireless interface can be located in the central part of the force measuring module. A signal-transparent plastic cover protects the wireless interface from damage and dirt. The wireless interface allows the force measuring module to be conveniently operated by the user. The measurement data from the force measuring module can also be sent via the wireless interface to an external screw terminal, based on which the screw parameters for the corresponding battery module can be automatically preset and then used during the semi-automatic or automatic crimping and screwing process.

[0022] According to another preferred example of the disclosure, the force measuring module comprises a housing with an energy storage device configured to supply the force measuring module with electrical energy. For example, the energy storage device can be a replaceable battery. The battery can supply the force measuring module with a voltage, preferably 12 volts. The force measuring module can also be operated, for example, via a power supply unit. The heat exchangers can be arranged side by side on the replaceable battery. A warning signal, such as a warning light or a warning display, allows the user to recognize whether the battery needs to be replaced. This prevents the force measuring module from interrupting the measurement due to insufficient power supply.

[0023] One aspect of the invention relates to a method for determining a force when inserting a battery module into a battery housing, comprising providing a force measuring module with a housing that essentially has the outer dimensions of the battery module; and at least one force sensor arranged in the housing and configured to detect a force when inserting the housing into the battery housing, inserting the force measuring module instead of the battery module into the battery housing, and detecting the force during insertion by the force sensor.

[0024] For example, the force measuring module can be inserted into the battery compartment of the battery housing using a workpiece gripper. Before inserting the force measuring module, a thermally conductive medium, such as a gap filler, can be applied to the battery compartment. The force measuring module can then be pressed into place in the battery compartment.

[0025] In a preferred embodiment, the shape and external dimensions of the battery module to be used are measured, and the shape and external dimensions of the force-measuring module housing are adapted to the shape and external dimensions of the respective battery module. For this purpose, the base, cover, and / or side walls of the force-measuring module are preferably shifted and locked relative to one another, allowing for flexible adaptation to different shapes and external dimensions of the force-measuring module housing. The adjustment of the housing's shape and external dimensions can be carried out manually by an operator by locking the brackets on the respective rail, or by electric actuators via an electronic control system.

[0026] For example, the force measuring module can have three force sensors, which are spatially distributed across its base and detect the force when the force measuring module is pressed. The measured values ​​can then be recorded and analyzed by the data processing system. After the force has been detected, the force measuring module can be removed from the battery compartment using the workpiece gripper, and a new battery module can be inserted into the battery compartment.

[0027] Furthermore, the force is measured when the integrated force measuring module is screwed onto the battery housing and / or a cover. Based on the measured forces and force changes in the force measuring module, the battery module can be screwed on using the workpiece gripper or a screw terminal.

[0028] Furthermore, in addition to measuring and evaluating pressing and screwing forces, the wetting of the heat-conducting medium in the battery compartment can also be analyzed during the pressing and screwing of the force measuring module.

[0029] According to the invention, the installed force measuring module is removed and the battery module is inserted into the battery housing, taking into account the forces previously measured on the installed force measuring module. The battery module can be inserted using the workpiece gripper.

[0030] Further features, advantages and details of the invention will become apparent from the following description of a preferred embodiment and from the drawings. Brief character description

[0031] The invention is explained in more detail below with reference to exemplary embodiments and the figures. The figures show: Figure 1 is an exploded view of a force measuring module according to a first example of the disclosure; Figure 2 is a perspective view of a force measuring module according to the first example of the disclosure; Figure 3 is a perspective view of a force measuring module with a battery compartment according to the first example of the disclosure; Figure 4 is a sectional view of a bottom surface with a force sensor and a central part according to a second example of the disclosure during pressing of the force measuring module; Figure 5 is a schematic representation of a method for determining a force when inserting a battery module into a battery housing.

[0032] The figures are merely schematic representations and serve only to illustrate the invention. Identical or equivalent elements are consistently identified by the same reference numerals.

[0033] The Fig. 1shows a force measurement module according to a first example of the disclosure in an exploded view.

[0034] The force measuring module 100 comprises a base surface 101. According to the first example of the disclosure, the base surface is connected to a central section 102 via three force sensors 104. The three force sensors 104 are arranged in a triangular pattern on the base surface 101 and attached to the central section 102. By evaluating the forces and force changes measured at the force sensors 104, a spatial stress distribution can be calculated based on averaging the respective forces and force changes with respect to the area between and with respect to the positions of the force sensors 104. In another example of the disclosure, more than three force sensors 104 are arranged differently in spatial distribution on the base surface 101, whereby a wide variety of spatial distributions are conceivable and corresponding evaluation methods at the positions of the force sensors 104 are possible.

[0035] A replaceable battery 105 is arranged on the central part 102, which supplies the force measuring module 100 with electrical energy. A warning display 112, also arranged on the central part 102, indicates when the battery 105 needs to be replaced. Two fans, acting as heat exchange units 106, are also arranged and attached to the central part 102. In another example of the disclosure, more than two fans 106 are attached to the central part 102. The fans 106 protect the force measuring module 100 from overheating and dissipate the heat generated during operation or maintain the temperature of the force measuring module 100 at a predetermined temperature; preferably at the temperature of the associated battery module 113 (not in Fig. 1 (shown) during pressing and screwing.

[0036] Furthermore, an on / off rocker switch 108 and a wireless interface 107 are arranged on the central part 102. The on / off rocker switch 108 serves to switch the force measuring module 100 on and off; preferably as part of an automated insertion of the force measuring module 100 into a battery housing. According to the first example of the disclosure, the wireless interface 107 is a WLAN interface. The force measuring module can be connected to an external data processing device via the wireless interface 107.

[0037] Furthermore, another data processing unit 111 is installed in the central section 102 and connected to a measuring amplifier 110 via a data network. The data processing unit 111 records the measured values ​​from the force sensors 104 in real time, analyzes them, and calculates the resulting forces and / or force changes. Based on the calculated forces and / or force changes, conclusions are drawn about the quality and any internal stresses that occur when pressing and screwing the force measuring module 100. The measuring amplifier 110 is also located on the central section 102. The measuring amplifier 110 increases the measurement accuracy of the force sensors 104.

[0038] The force measuring module 100 also includes a cover 103, which protects the force measuring module 100 from damage and dirt.

[0039] The Fig. 2shows the force measurement module in a perspective representation according to the first example of the Revelation.

[0040] The base 101, the middle section 102, and the cover 103 of the force measuring module 100 are fastened by screws. The housing of the force measuring module 100 corresponds to the shape and external dimensions of the battery module 113 to be used.

[0041] The Fig. 3 The force measuring module with a battery compartment 114 is shown in a perspective view according to the first example of the revelation.

[0042] The base 101 of the force measuring module 100 is floatingly mounted in the battery compartment 114, since a gap filler 115 is applied to the battery compartment 114 before the force measuring module 100 is pressed in. In the example shown, the gap filler 115 is applied in a strip to the base of the battery compartment 114. The battery compartment 114 includes several mounting tabs 116. The force measuring module 100 is screwed to the battery housing using the mounting tabs 116. The force measuring module 100 can be individually inserted into its assigned battery compartment 114 and screwed in place, so that immediately afterwards the assigned battery module 113 is pressed in and screwed in, taking into account the measured forces and force changes in the force measuring module 100. This procedure ensures that the internal voltages within the assigned battery module 113 of the respective battery compartment 114 are minimized.Alternatively, it is proposed that, in a first step, all battery compartments 114 of the battery housing are each fitted with force measuring modules 100 and screwed in place. Subsequently, the force measuring modules 100 are individually removed from the battery compartments 114 and replaced by corresponding battery modules 113. The respective battery modules 113 are pressed and screwed in place based on the measured forces and / or force changes of the force measuring module 100 assigned to the respective battery compartment 114. The advantage of this procedure is that the internal stresses within the entire battery housing, and not just in relation to a single battery compartment 114, are minimized.

[0043] The Fig. 4 shows a cross-sectional view of the floor surface with the force sensor and the central part according to a second example of the disclosure during the grouting of the force measuring module.

[0044] The force sensor 104 is attached to the central part 102 by screws 118. According to the second example of the disclosure, the base surface 101 includes a cover 119. Furthermore, the force sensor 104 is attached to the base surface 101 by shoulder screws 117. Only the tip of the screw neck of the shoulder screw 117 is threaded. The remaining part of the screw neck has a smooth surface, allowing the shoulder screw 117 to move linearly within a screw hole. The base surface 101 is connected to the central part 102 only via the shoulder screws 117 and the force sensor 104. When the force measuring module 100 is pressed in, the shoulder screw 117 is pressed into the screw hole. Also, in the Fig. 4 The force flow 120 during the pressing of the force measuring module 100 is shown in the form of lines. The forces are transmitted via the screws 118 and the force sensor 104.

[0045] The Fig. 5shows a schematic representation of a method for determining a force when inserting a battery module into a battery housing.

[0046] In a first step (S1), the force measurement module 100 is provided with the housing.

[0047] The force measuring module 100 has the shape and external dimensions of the battery module 113 or is adapted to the shape and external dimensions of the battery module to be used.

[0048] In a second step (S2) a gap filler 115 is applied to a bottom surface of the battery compartment 114.

[0049] In a third step (S3), the force measuring module 100 is inserted into the battery compartment 114 of the battery housing. The force measuring module 100 is inserted into the battery compartment 114 using a workpiece gripper.

[0050] In a fourth step (S4), the forces and / or changes in force during the insertion of the force measuring module 100 into the battery compartment 114 are detected by the force sensors 104. The force measuring module 100 is subjected to a pressing force when inserted into the battery compartment 114. According to the exemplary embodiment, three force sensors 104 are arranged on the base surface 101 of the force measuring module 100. The individual forces and / or changes in force of the respective force sensors 104 are measured. The data processing unit 111 records the measured values ​​in real time and calculates the resulting force when pressing the force measuring module 100 into the battery compartment 114.

[0051] In a fifth step (S5), the force sensors 104 detect the forces exerted when the force measuring module 100 is screwed onto the battery housing and onto a cover of the battery housing. In a further embodiment, the forces can be detected when screwing the force measuring module 100 onto the battery housing or onto a cover of the battery housing.

[0052] In a sixth step (S6), the force measuring module 100 is removed from the battery compartment 114 using a workpiece gripper, and then the battery module 113 is inserted into the battery housing. The previously measured values ​​from the force sensors 104 of the force measuring module 100 are taken into account when the battery module is inserted. REFERENCE MARK LIST

[0053] 100 Force measuring module 101 Base area 102 Center section 103 Cover 104 Force sensor 105 Battery 106 Heat exchanger unit 107 Wireless interface 108 On / Off rocker switch 110 Measuring amplifier 111 Data processing unit 112 Warning display 113 Battery module 114 Battery compartment 115 Gap filler 116 Mounting tab 117 Shoulder screw 118 Screw 119 Cover 120 Force flow

Claims

1. Method for determining a force during insertion of a battery module (113) into a battery housing, comprising: providing a force measuring module (100) with a housing (S1) which substantially corresponds to the external dimensions of the battery module (113); and at least one force sensor (104) which is arranged in the housing and configured to detect a force during insertion of the housing into the battery housing; inserting the force measuring module (100), instead of the battery module (113), into the battery housing (S3); detecting the force (S4) during insertion by means of the force sensor (104), wherein the inserted force measuring module is subsequently removed and the battery module is inserted into the battery housing while taking into account the forces previously measured on the inserted force measuring module.

2. Method according to claim 1, comprising detecting a force during screwing of the inserted force measuring module (100) to the battery housing and / or to a cover (S5).

3. Method according to one of claims 1 or 2, comprising determining the shape and the external dimensions of the battery module (113) and adapting the shape and the external dimensions of the housing of the force measuring module (100) to the shape and the external dimensions of the battery module (113) prior to inserting the force measuring module (100) into the battery housing.