Method for separating a first component body from a second component body

Abstract

A method is presented for separating a first and a second component body that are bonded together by an adhesive. The method includes aligning a lifting tool with a key slot that extends through the first component body. The lifting tool includes a plurality of ramp pins that project outward from the lateral sides of a tool shank. The key slot includes a plurality of helical ramps located on the lateral sides of a through-hole. The lifting tool is inserted into the key slot until a distal tip of the tool shank abuts the second component body. The lifting tool rotates in the key slot to translate the ramp pins along the helical ramps, causing the distal tip of the tool shank to press against the second component body, thereby separating the two component bodies.

Description

[0001] This description generally relates to components with multi-piece bodies. More specifically, parts of this description relate to tools and methods for disassembling electronic components with multi-piece metal castings bonded by metal-to-metal adhesives.

[0002] Today's production vehicles, such as the modern automobile, are originally equipped with a network of control units, sensors, communication devices, accessories, and other electronic components distributed throughout the vehicle body. As the power and processing requirements of these vehicle components continue to increase, so does the waste heat generated during vehicle operation. To prolong the operation of the vehicle's various electronic components, most automobiles employ passive and active thermal management features to regulate the components' operating temperatures. The vehicle's powertrain control module (PCM), for example, may be characterized by an integrated electronic control unit (ECU) with multiple system-on-chip (SOC) circuit board assemblies sealed within a metal enclosure.The ECU cartridge can be securely bonded to a cast metal housing of a traction motor / generator unit (MGU) using a thermally conductive metal-to-metal adhesive. This adhesive bond thermally bonds the ECU to the MGU, transferring heat from the ECU to the MGU housing, which features a larger thermal mass and active cooling channels for heat dissipation. It may be necessary to repair or replace the ECU; however, the metal-to-metal adhesive forms a high-strength, "weld-like" bond that is not easily separated with standard tools.

[0003] US 6 298 534 B1 describes an apparatus and a method for separating components of a processing system, wherein the components are connected to one another and adhere to one another after processing.

[0004] It can be considered an object to provide an improved method for separating a first component body from a second component body.

[0005] The object is achieved by a method according to claim 1. Furthermore, as application examples and to facilitate understanding of the method according to the invention, lifting tools for separating multi-part components, methods for manufacturing and using such lifting tools, and motor vehicles with electronic components having multi-part metal castings that are separated using such lifting tools are described below. For illustrative purposes and without limitation, a key slot with a pair of helical ramps is formed or milled through an upper casting (for example, a cast aluminum cartridge of a central computer unit (CCU)), which is bonded to a support surface of a lower casting (for example, a cast aluminum chassis of an electronic control unit (EDU)) with a thermally conductive adhesive (for example, an indium-based thermal paste).A high-strength metal lifting tool is inserted into the complementary key slot so that a distal tip of the tool rests against the support surface of the lower casting. The lifting tool comprises an elongated shaft with a pair of ramp pins projecting outward from opposite sides of the shaft. After insertion into the key slot, the lifting tool is rotated, for example, approximately 90 degrees, so that the ramp pins slide along and press against the undersides of the helical ramps of the key slot, forcing the distal tip of the shaft against the lower casting. This breaks the adhesive bond and lifts the upper casting from the lower casting.

[0006] In at least some applications, the lifting tool is a machined steel component manufactured as a one-piece structure with the shank extending coaxially from a distal end of a hex drive shaft. The drive shaft and the lifting tool shank may both have a right circular cylinder geometry, with the drive shaft having a larger diameter than the shank. As a further option, the ramp pins may have right circular cylinder geometries and project radially outward from diametrically opposite sides of the shank. An optional nylon pad may be attached to the distal tip of the shank or to the mounting surface of the lower casting for insertion between the lifting tool and the lower casting to facilitate tool rotation and to protect the casting.It is also conceivable for the key slot to be cast or machined as a through-hole extending through the mating halves of the CCU cartridge, and for the helical ramps to be integrated into the lower half of the cartridge. Each helical ramp can be arc-shaped with a central arc angle of 90°, and each ramp can be located on an opposite side of the key slot.

[0007] Parts of this description relate to simplified, cost-effective, and efficient methods for disassembling multi-part components without damaging the components. A method according to the invention is presented for separating first and second component bodies that are bonded together by means of an adhesive.This inventive method comprises: aligning a lifting tool with a key slot extending through the first component body, the lifting tool having a plurality of ramp pins projecting outwardly from the lateral sides of a tool shank, and the key slot having a plurality of helical ramps located on the lateral sides of a through-hole; inserting the lifting tool into the key slot such that a distal tip of the tool shank abuts the second component body; and rotating the lifting tool in the key slot such that the ramp pins slide along the helical ramps, whereby the lifting tool translates and presses the distal tip of the tool shank against the second component body, thereby separating the first component body from the second component body.

[0008] Further portions of this description relate to lifting tools for separating component bodies bonded together by an adhesive. In one example, a lifting tool includes a cylindrical tool shank formed wholly or partially from a metallic material. The tool shank is structurally shaped and sized to align with and insert into a complementary key slot extending through a first (upper) component body. The key slot includes a through-hole having first and second helical ramps located on opposite lateral sides of the through-hole. A distal tip of the tool shank is structurally shaped and sized to abut the second component body when the lifting tool is inserted into the key slot.First and second cylindrical ramp pins are formed integrally with the tool shank and project radially outward from opposite lateral sides of the tool shank, being diametrically opposed. The tool shank is shaped and sized to be rotated in the key slot. By rotating the lifting tool in the key slot, the ramp pins are shaped and sized to slide along the undersides of the helical ramps; this causes the lifting tool to move rectilinearly toward a second (lower) component body, causing the distal tip of the tool shank to press against the second component body, thereby rupturing the adhesive and lifting the first component body from the second component body.

[0009] Further portions of this description relate to systems for disassembling multi-part component bodies. In one example, a system includes a first component body that is secured to a second component body using an adhesive. The first component body is provided with a key slot extending through the first component body. This key slot includes a through-hole with a plurality of helical ramps located on the lateral sides of the through-hole. The system also includes a lifting tool constructed with a plurality of ramp pins projecting outwardly from the lateral sides of a tool shank. The tool shank is designed to be aligned with and insertable into the key slot such that a distal tip of the tool shank abuts the second component body.The tool shank is also designed to rotate within the key slot. The ramp pins are designed to slide along the helical ramps when the lifting tool is rotated within the key slot. This forces the distal tip of the tool shank against the second component body, which in turn causes the adhesive to crack and separate the first component body from the second component body.

[0010] In all of the disclosed tools, systems, and methods, the lifting tool may include first and second ramp pins projecting radially outward from opposite first and second lateral sides of the tool shank, respectively. In this case, the first ramp pin may have a first cylindrical shape with a first diameter, and the second ramp pin may have a second cylindrical shape with a second diameter. The ramp pins may have a common cylindrical shape with a common diameter. As a further option, the common cylindrical shape of the ramp pins may be a right cylinder. Additionally, the first ramp pin may be diametrically opposed to the second ramp pin, such that the ramp pins project from each other in opposite directions.It may be desirable for the lifting tool, including the tool shaft, ramp pins and drive shaft, to be integrally molded as a one-piece structure, for example from high-strength metallic, polymeric and / or composite materials.

[0011] In all disclosed tools, systems, and methods, the lifting tool may include a hex drive shaft with a hexagonal crown at a proximal end of the drive shaft and the tool shaft extending coaxially from a distal end of the drive shaft. In this case, the hex drive shaft of the lifting tool may be inserted into a complementary hex drive socket integrated into or attached to a manual tool handle or power drill. As a further option, the diameters of the ramp pins may be smaller than the diameter of the hex drive shaft and the diameter of the tool shaft. The disclosed lifting tools, systems, and methods may be used for electronic and non-electronic components, metallic and non-metallic components, and for automotive and other applications.

[0012] In any of the disclosed tools, systems, and methods, the key slot may include first and second helical ramps located on opposing first and second lateral sides of the key slot, respectively. Each helical ramp may be arcuate, with a central arc angle of approximately 90 degrees or less. As a further option, the helical ramps may each terminate at a respective ramp wall, for example, at the lowermost ends of the ramps. Furthermore, the helical ramps may have a longitudinal height that extends less than half the longitudinal length of the key slot. An uppermost end of the key slot may include an irregularly shaped keyhole shaped and sized to receive the tool shank and ramp pins of the lifting tool.

[0013] In all of the disclosed tools, systems, and methods, the distal tip of the tool shank includes a nylon pad or other compressible polymeric material. In this case, upon insertion of the lifting tool into the key slot, the nylon pad is pressed against a portion of the second component body not covered by the adhesive. Although not limiting per se, it may be desirable for the first component body to be constructed entirely or partially from a first metallic material (e.g., cast aluminum), the second component body to be constructed entirely or partially from a second metallic material (e.g., cast aluminum), and the lifting tool to be constructed entirely or partially from a third metallic material (e.g., cast steel) that is different from the first and second metallic materials and is more rigid.In this case, the adhesive is a thermally conductive metal-to-metal adhesive (e.g., a high-strength, pressure-sensitive TIM paste). Alternatively, the bonded components can be made of other rigid and elastic materials, including ceramics, polymers, and composites. The lifting tool can be made of high-strength plastics, and the adhesive can be a commercially available plastic-to-plastic, plastic-to-metal, ceramic-to-ceramic, and so on. Fig. 1 is a perspective view of a representative multi-part component body with a representative lifting tool for separating the component body from a component support surface. Fig. 2 is an enlarged perspective view of the representative lifting tool of Fig. 1 adjacent to a complementary key slot in the representative multi-part component body. Fig. 3 is a cross-sectional side view of the representative lifting tool of Fig. 1, which is inserted into the key slot and rotated to thereby separate the representative multi-part component body from the component support surface.

[0014] Fig. 1 shows a representative example of a multi-part component, generally designated 100, which is illustrated herein for purposes of discussion as a central computer unit (CCU) of a motor vehicle 10 having a vehicle body 14 and a plurality of wheels 22, wherein like reference numerals refer to like features throughout the several views. The illustrated vehicle CCU 100 is merely an exemplary application with which portions of this description may be practiced. Likewise, the use of the present concepts for disassembling cast metal housings of vehicle electronic components should be understood as a non-limiting implementation of the disclosed features.It is understood that the parts and features of this description can also be applied to other vehicle components, that they can be used for the disassembly of non-metallic and non-electronic devices, and that they can be used for both automotive and non-automotive applications. Furthermore, only selected features of the vehicle component and the lifting tool are shown and described in detail below. Nevertheless, the components and tools discussed herein may incorporate numerous additional and alternative features to perform the various methods and functions of this description.

[0015] The vehicle CCU 100 from Fig. 1 can be typified as an integrated electronic control unit (ECU) responsible for controlling the dynamic behavior of a motor vehicle, which may include functions such as throttle, steering, braking, traction control, and so on.

[0016] In the illustrated example, the CCU 100 may include a protective and weatherproof two-piece CCU cassette 102 consisting of a first (upper) cassette shell 104 securely mounted to a second (lower) cassette shell 106, for example, by a distributed array of hex-head screws 108. The mating cartridge shells 104, 106 may be made of cast aluminum or another rigid but thermally conductive material that facilitates heat dissipation from the CCU 100. Although not visible in the illustrated views, one or more system-on-chip (SOC) printed circuit board assemblies (PCBAs) may be sealed inside the CCU cassette 102 and connected to other vehicle subsystems via a series of terminals that mate with various external electrical connectors (not shown).

[0017] As in Fig. 3, the CCU 100 is securely affixed to a cast aluminum chassis 110 of an electronic drive unit (EDU) using a thermally conductive adhesive, such as a TIM paste 112. The EDU may be an integrated powertrain unit that includes an electric traction motor / generator (MGU), an automatic transmission, and a traction power inverter module (TPIM). For the purposes of the following discussion, the CCU cassette 102 may be a representative example of a "first component body" and the cast aluminum chassis 110 may be a representative example of a "second component body." However, it is contemplated that the CCU 100 could take on other form factors and be bonded to another vehicle component without departing from the intended scope of this description.

[0018] During use of the vehicle CCU 100, the cassette 102 or the CCU's internal electronics may become damaged and require repair or replacement with a new, "serviceable" unit. However, the TIM paste 112 securing the CCU 100 to the EDU chassis 110 forms a weld-like bond that cannot be easily broken with common tools to enable such removal and servicing of the CCU 100. Tools, systems, and methods are described below that enable simplified and efficient removal of the vehicle CCU 100 without damaging the cassette 102 or the chassis 110. As a non-limiting example, a helical ramp is integrated into an upper cast aluminum housing body of a first component that is connected to a lower cast aluminum housing body of a second component.A machined steel lifting tool has pins or ribs with curved surfaces that slide on the ramp surfaces of the helical ramp feature when torque is applied to the lifting tool. Utilizing the mechanical advantage between the helical ramp feature and the pins / ribs of the lifting tool, the lifting tool pushes the upper housing body away from the lower housing body, simultaneously breaking the adhesive bond between the mating surfaces of the first and second components.

[0019] In at least some system configurations, the helical ramp is integrated into the upper housing body by aluminum casting; if desired, multiple ramps can be molded into a single component. The lifting tool can be precision-machined from high-strength stainless steel and manufactured as a standalone tool (for example, integrated into a handheld tool) or as an interchangeable tool insert (for example, detachable from a socket wrench or power screwdriver). An optional nylon pad can be inserted between the lower housing body and an end face of the guided diameter of the lifting tool to facilitate rotating the lifting tool without denting or otherwise damaging the lower housing body.The self-adhesive TIM adhesive paste material can be clamped between the mating surfaces of the upper and lower housing bodies; a selected section of the mating surface can be without TIM paste to allow unobstructed rotation of the lifting tool against the housing body.

[0020] During part-to-part assembly, the bottom of the cast aluminum upper housing body is bonded to the top of the cast aluminum lower housing body using TIM adhesive paste. During part servicing, the lower end of a machined steel guide-diameter lifting tool is inserted into the open upper end of the helical ramp in the upper housing body. The lifting tool is forced down the helical ramp until a nylon pad at the distal tip of the lifting tool rests against the lower housing body and the rounded pins / ribs of the lifting tool are aligned with the helical track of the ramp.A torsional force is applied to the lifting tool, causing the tool shaft to rotate a quarter turn and the tool's pins / ribs to slide along the helical ramp. This forces the lifting tool and nylon pad against the surface of the lower housing body, while simultaneously exerting a lifting force on the upper housing body. This lifting force causes the TIM adhesive paste to break, causing the upper housing body to lift away from the lower housing body.

[0021] In Fig. 2, a non-limiting example of a lifting tool 120 is illustrated alongside a non-limiting example of a key slot 130 extending through the lower cartridge half 106 of the CCU cartridge 102. The illustrated lifting tool 120 includes an elongated tool shaft 122 having one or more slidable ramp pins 124 projecting outwardly from one or more lateral sides of the shaft 122. For convenience, the lifting tool 120 may be manufactured with a first (left) ramp pin 124A projecting radially outwardly from a first (left) lateral side of the shaft 122 and a second (right) ramp pin 124B projecting radially outwardly from a second (right) lateral side of the shaft 122. The first ramp pin 124A may be diametrically opposed to the second ramp pin 124B such that the two pins 124A, 124B extend in opposite directions from each other.It is contemplated that the lifting tool 120 may include more or fewer than two ramp pins 124, that it may include ramp pins 124 arranged in different patterns, and / or that it may include ramp pins 124 that are coplanar or axially offset from one another.

[0022] To facilitate the alignment, mating, and sliding contact of the ramp pins 124 with the helical ramps 132 of the key slot 130, the first ramp pin 124A may have a first cylindrical shape with a first (pin) diameter D P1 and the second ramp pin 124B has a second cylindrical shape with a second (pin) diameter D P2 have ( Fig. 3). To simplify design and manufacture, both ramp pins 124A, 124B may have a common cylindrical shape with a common diameter (i.e., diameter D P1 = Diameter D P2). According to the illustrated example, both ramp pins 124A, 124B are straight cylinders, where the longitudinal length of the cylinder is smaller than its diameter. Alternative designs may include cylindrical ramp pins with oval, elliptical, or teardrop-shaped cross-sections. Unlike other commercially available lifting tool designs, the lifting tool 120 may be characterized by having no helical threads, no moving parts, and / or no electrical parts.

[0023] For lifting tool configurations designed for use with a complementary hand tool or power tool, the lifting tool 120 may include an elongated hex drive shaft 126 with a hexagonal crown 128 projecting from a proximal (upper) end of the shaft 126, and the tool shaft 122 coaxially projecting from a distal (lower) end of the shaft 126. In this case, the hex crown 128 of the hex drive shaft 126 may be inserted into a hex drive socket (not shown) of a hand-operated tool (for example, a socket wrench or a multi-bit screwdriver) or a power tool (for example, the chuck of an electric screwdriver). As shown in the Fig. 2 and Fig. 3, the hexagonal drive shaft 126 can have a third cylindrical shape with a third (shaft) diameter D S3and the tool shank 122 may have a fourth cylindrical shape with a fourth (shank) diameter D S4 which is smaller than the shaft diameter D S3 . In the example shown, the pin diameters D P1 , D P2 the left and right ramp pins 124A, 124B both smaller than the shaft diameter D S3 of the hexagon drive shaft 126 and the shaft diameter D S4 of the tool shank 122. It may be desirable for the lifting tool 120, including the tool shank 122, the ramp pins 124, and the drive shaft 126 with hex crown 128, to be integrally molded as a one-piece structure, for example, from high-strength metallic, polymeric, and / or composite materials.

[0024] To remove the vehicle CCU 100 from the EDU chassis 110, the lifting tool 120 is inserted into the key slot 130 extending through the CCU cassette 102 and rotated therein. The key slot 130 is in Fig. 3 with a through hole 134 extending from the top to the bottom of the lower cartridge shell 106 of the CCU cartridge 102. To facilitate the insertion of the lifting tool 120 into the key slot 130, the upper cartridge case 104 of the CCU cartridge 102 can be provided with a key groove pocket 136 ( Fig. 1) recessed into a side edge of the sleeve 104 and aligned with the key slot 130. The illustrated key slot 130 includes one or more helical ramps 132 projecting inwardly from one or more lateral sides of the through-hole 134. For example, the key slot 130 may include a first (left) helical ramp 132A located on a first (left) lateral side of the key slot 130 and slidably receiving the first ramp pin 124A, and a second (right) helical ramp 132B located on a second (right) lateral side of the key slot 130 and slidably receiving the second ramp pin 124B. It is contemplated that the key slot 130 may include more or fewer than two helical ramps 132, which may be coplanar or axially offset from one another.

[0025] Fig. Figure 2 shows the underside of the CCU cartridge 102 to better illustrate some of the key structural details of the key slot 130. For example, both helical ramps 132A, 132B may be arcuate, with an average arc angle Θ CA of approximately 90 degrees or less. As a further option, each helical ramp 132A, 132B may terminate at a corresponding elongated ramp wall 138A and 138B located at the lowermost end of the ramp 132 and serving to prevent further displacement of the ramp pin 124 sliding on the ramp 132. In addition, the helical ramps 132A, 132B of the key slot may have a ramp height H LR which extend over less than half of the longitudinal slot length L LS of the key slot 130 (for example H LR ≤ 0.10 - L LS). An uppermost end of the key slot 130 may include an irregularly shaped keyhole 140 shaped and sized to receive the tool shank 122 and the ramp pins 124 of the lifting tool 120. Furthermore, the first helical ramp 132A may be diametrically opposed to the second helical ramp 132B, with both ramps 132A, 132B sloping in the same direction (for example, clockwise in Fig. 1).

[0026] To remove the vehicle CCU 100 from the EDU chassis 110, the lower end of the lifting tool 120 is inserted through the keyhole 140 into the key slot 130. After insertion, the lifting tool 120 is moved straight down until the distal tip of the tool shaft 122 rests against the top of the EDU chassis 110. In Fig. 3, the lifting tool 120 is shown with a nylon pad 142 attached to the distal tip of the tool shaft 122. In this case, the nylon pad 142 is pressed against the top of the EDU housing 110 when the lifting tool 120 is inserted into the key slot 130. When the tool 120 is fully inserted into the slot 130, each ramp pin 124A, 124B is aligned with its respective key slot ramp 132A, 132B. After the tip of the tool shaft 122 with the nylon pad 142 rests against the EDU housing 110, the lifting tool 120 is rotated in the key slot 130, for example, a quarter turn or approximately 90° counterclockwise in Fig.1. Rotating the lifting tool 120 causes the ramp pins 124A, 124B to slide along the sloping undersides of the helical ramps 132A, 132B. Sliding the pins 124 on the ramps 132 causes the distal tip of the tool shaft 122 to press against the EDU housing, which in turn causes the TIM adhesive paste 112 to rupture and the CCU cartridge 102 to detach from the housing 110.

Claims

[1] A method for separating a first component body (102) from a second component body (110), wherein the first component body (102) and the second component body (110) are joined together by means of an adhesive (112), the method comprising: Aligning a lifting tool (120) with a key slot (130) extending through the first component body (102), the lifting tool (120) comprising a tool shank (122) having a plurality of ramp pins (124A, 124B) projecting outwardly from lateral sides of the tool shank (122), and the key slot (130) comprising a through hole (134) having a plurality of helical ramps (132A, 132B) located on lateral sides of the through hole (134); Inserting the lifting tool (120) into the key slot (130) so that a distal tip of the tool shank (122) abuts the second component body (110); and Rotating the lifting tool (120) in the key slot (130) so that the ramp pins (124A, 124B) slide along the helical ramps (132A, 132B), thereby pressing the distal tip of the tool shank (122) against the second component body (110) and thereby separating the first component body (102) from the second component body (110). [2] The method of claim 1, wherein the plurality of ramp pins (124A, 124B) comprise first and second ramp pins (124A, 124B) projecting radially outwardly from opposite first and second lateral sides of the tool shank (122), respectively. [3] The method of claim 2, wherein the first ramp pin (124A) has a first cylindrical shape with a first diameter and the second ramp pin (124B) has a second cylindrical shape substantially the same as the first cylindrical shape with a second diameter substantially the same as the first diameter. [4] The method of claim 3, wherein the first and second cylindrical shapes are right circular cylinders and wherein the first ramp pin (124A) is diametrically opposite the second ramp pin (124B). [5] The method of claim 3, wherein the lifting tool (120) further comprises a hex drive shaft, the tool shaft (122) projecting coaxially from a distal end of the hex drive shaft, the method further comprising inserting the hex drive shaft of the lifting tool (120) into a hex drive socket of a manual tool handle or an electric drill. [6] The method of claim 5, wherein the hex drive shaft has a third cylindrical shape with a third diameter and the tool shaft (122) has a fourth cylindrical shape with a fourth diameter that is smaller than the third diameter. [7] The method of claim 6, wherein the first and second diameters of the first and second ramp pins (124A, 124B) are smaller than the third diameter of the hex drive shaft and the fourth diameter of the tool shaft (122). [8] The method of claim 1, wherein the lifting tool (120) comprising the tool shank (122) and the plurality of ramp pins (124A, 124B) is integrally formed as a one-piece structure. [9] The method of claim 1, wherein the plurality of helical ramps (132A, 132B) comprise first and second helical ramps (132A, 132B) located on opposite first and second lateral sides of the key slot (130), respectively. [10] The method of claim 9, wherein the first and second helical ramps (132A, 132B) are arcuate and have an average arc angle of about 90 degrees or less.

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