JP2014221523A - Joining method, and joined body produced thereby - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joining method which can prevent occurrence of a defective external appearance of a joined member, can prevent occurrence of a rupture of the joined member, and can satisfactorily assure the joining strength between joining members, and to provide a joined body.SOLUTION: The joining method comprises the steps of: disposing a resin member so as to overlap a metallic member; holding a peripheral part of the outer peripheral edge of the resin member positioned in an overlapped area of the metallic member; pressing a rotary tool to the surface of the metallic member in such a state that a distance between the outer periphery of a shoulder part of the rotary tool and the outer peripheral edge of the resin member is kept within a predetermined range; and rotating the shoulder part. The predetermined range is determined so that the overlapped area of each of the resin member and the metallic member is melted by the rotation of the shoulder part and the resin member is joined to the metallic member. The joined body produced by using the joining method is also provided.

Description

  The present invention relates to a method for joining a resin member and a metal member using a rotary tool having a cylindrical shoulder portion that can rotate around a longitudinal axis, and is further manufactured using such a joining method. It relates to the joined body.

  In recent years, Friction Stir Welding (FSW) has been adopted for joining resin members and metal members. The friction stir welding method includes a shoulder portion formed in a cylindrical shape, and a probe portion formed in a cylindrical shape having a smaller diameter than the shoulder portion at a longitudinal end of the shoulder portion, and is provided in the longitudinal direction of the shoulder portion. A rotation tool configured to be rotatable about an axis is generally used. In an example of a conventional joining method using such a friction stir welding method, a metal member formed in a plate shape is placed on the surface of a resin member formed in a plate shape, and the metal member is arranged in the thickness direction of the metal member. With the axis of the rotary tool facing, press the probe part of the rotary tool against the overlapping area of the metal member that overlaps the resin member, rotate the shoulder part together with the probe part around its longitudinal axis, and this rotation The resin member and the metal member are melted using the generated frictional heat to join the resin member and the metal member. (For example, see Patent Document 1 and Patent Document 2)

  Moreover, in another example regarding the conventional joining method, the outer peripheral edge of the resin member formed in the plate shape and the outer peripheral edge of the metal member formed in the plate shape are arranged to face each other, and the rotating tool is arranged in the thickness direction of the metal member. The probe part of the rotary tool is pressed against the area around the abutting part of the metal member located in the vicinity of the abutting part between the resin member and the metal member with the axis of The resin member and the metal member are melted by rotating around the axial direction and the frictional heat generated by the rotation is used to join the resin member and the metal member. (For example, refer to Patent Document 2, in particular, FIG. 5 of Patent Document 2)

JP 2010-158885 A JP 2012-170975 A

  However, in an example relating to a conventional joining method, when the probe portion of the rotary tool is rotated while being pressed against the overlapping region of the metal member, a load is applied to the overlapping region of the resin member that overlaps the metal member, and the melting is performed. The finished metal member is pushed out to the resin member side. As a result, the metal member is deformed so that a bump is formed on the surface of the metal member in contact with the surface of the resin member, and a groove is formed on the surface of the metal member pressing the probe. In many cases, the surface of the metal member that presses the probe becomes the appearance surface, and the appearance defect occurs due to the groove on the surface. In addition, when the metal member is formed thin, the metal member may be broken due to the deformation of the metal member.

  In another example related to the conventional joining method, since the outer peripheral edge of the resin member and the outer peripheral edge of the metal member are merely joined, the area of the joint between the resin member and the metal member is not sufficient, and the resin member In addition, it is difficult to sufficiently secure the bonding strength of the metal member.

  The present invention has been made in view of such circumstances, and its purpose is to prevent the appearance failure of the joining member, to prevent the joining member from being broken, and the joining strength between the joining members. It is in providing the joining method and joined body which can fully ensure.

  In order to solve the problem, a joining method according to an aspect of the present invention joins a resin member and a metal member using a rotary tool having a cylindrical shoulder portion configured to be rotatable around a longitudinal axis. A method of joining, the step of placing the resin member on a part of the metal member, and the periphery of the outer peripheral edge of the resin member located in the overlapping region of the resin member overlapping the part of the metal member Pressing a portion in a direction from the resin member toward the metal member, and a distance between an outer periphery of a shoulder portion of the rotary tool and an outer peripheral edge of the resin member that is positioned on the surface of the metal member. While maintaining within a predetermined range, the rotary tool is pressed against the surface of the metal member in a direction from the resin member toward the metal member, and the shoulder portion is rotated. Wherein the door, said predetermined range, said respective overlap regions of the resin member and the metal member by the rotation of the shoulder portion is melted, the resin member and the metal member is defined as bonded. For this reason, the location where the resin member is pressed in order to hold the resin member and the metal member and the location where the rotary tool is pressed are arranged apart from each other, so that the resin member acts to promote deformation of the resin member. Load to be reduced. As a result, the deformation of the resin member and the deformation of the metal member due to the deformation can be prevented, the appearance failure of the resin member and the metal member can be prevented, and the occurrence of the breakage of the resin member and the metal member can be prevented. . In addition, since the joint portion can be formed in a region where the surface of the resin member and the surface of the metal member overlap, for example, by increasing the amount of heat generated during rotation of the shoulder portion of the rotary tool, the area of the joint portion Can be secured sufficiently. Therefore, it is possible to sufficiently secure the bonding strength between the resin member and the metal member.

  In the joining method according to one aspect of the present invention, the predetermined range is larger than 0 mm and smaller than 10 mm. Furthermore, in the joining method according to one aspect of the present invention, it is preferable that the predetermined range is greater than 0 mm and 4 mm or less. Therefore, the overlapping region of the resin member and the metal member is reliably melted by the rotation of the shoulder portion, and the resin member and the metal member can be reliably joined. Furthermore, the area of the joint portion can be sufficiently secured, and the joint strength between the resin member and the metal member can be sufficiently secured.

  In the joining method according to an aspect of the present invention, the predetermined range is further determined such that burrs generated in the metal member due to rotation of the shoulder portion bite into an overlapping region of the resin member. Therefore, the resin member and the metal member are firmly bonded by the burr generated in the metal member, and the bonding strength between the resin member and the metal member can be sufficiently secured.

  The joined body which concerns on 1 aspect of this invention is produced by joining the said resin member and the said metal member using the joining method which concerns on the one aspect | mode of this invention mentioned above. Therefore, in the joined body according to one aspect of the present invention, the appearance failure of the resin member and the metal member can be prevented, the occurrence of breakage of the resin member and the metal member can be prevented, and the bonding strength of the resin member and the metal member can be prevented. Is sufficiently secured.

  According to the joining method and joined body which concern on 1 aspect of this invention, generation | occurrence | production of the appearance defect of a joining member can be prevented, generation | occurrence | production of the fracture | rupture of a joining member can be prevented, and the joint strength between joining members can fully be ensured.

It is sectional drawing which shows typically the joined body of the process in which the resin member and the metal member are joined using the joining method which concerns on embodiment of this invention. It is a top view of the joined body which joined the resin member and the metal member using the joining method concerning the embodiment of the present invention. It is AA sectional drawing of FIG. It is sectional drawing which shows typically the joined body in the process in which the resin member and the metal member are joined in Example 4. FIG.

  The joining method and joined body concerning the embodiment of the present invention are explained. The joined body according to the present embodiment will be described. 2 and 3 are photographs taken of the joined body 1 according to the present embodiment. As shown in FIGS. 1 to 3, the joined body 1 includes a resin member 2 and a metal member 3 formed in a substantially plate shape. The substantially plate-shaped resin member 2 has a front side surface 2a and a back side surface 2b facing the front side surface 2a. The substantially plate-shaped metal member 3 faces the front side surface 3a and the front side surface 3a. And a back side surface 3b. As shown in FIGS. 1 and 3, the resin member 2 is disposed so as to overlap a part of the metal member 3. Specifically, the resin member 2 is metal in a direction from the front side surface 2 a toward the back side surface 2 b. It arrange | positions so that a part of surface side 3a of the member 3 may be contacted. In such an arrangement relationship, the overlapping region 2c of the resin member 2 overlapping the metal member 3 and the overlapping region 3c of the metal member 3 overlapping the resin member 2 are joined. As shown in FIG. 3, a burr 3d is formed on the front side surface 3a of the overlapping region 3c of the metal member 3 so as to protrude from the back side surface 2b of the resin member 2 toward the front side surface 2a. The burr 3d bites into the overlapping region 2c in the resin member 2. Further, as shown in FIG. 2, a tool trace 3 e extending along the outer peripheral edge 2 d of the overlapping region 2 c of the resin member 2 is formed on the front side surface 3 a of the metal member 3.

  The joining method according to this embodiment will be described. First, the rotating tool 4 used in the joining method according to the present embodiment will be described. As shown in FIG. 1, the rotary tool 4 includes a shoulder portion 4a formed in a cylindrical shape, and a probe portion 4b formed in a cylindrical shape at the distal end in the longitudinal direction of the shoulder portion 4a. The central axis in the longitudinal direction of the probe part 4b and the central axis in the longitudinal direction of the shoulder part 4a are arranged on the same rotational axis 4c, and the diameter of the probe part 4b is smaller than the diameter of the shoulder part 4a. Such a rotating tool 4 is configured to be rotatable about a rotation axis 4c.

  A method for joining the resin member 2 and the metal member 3 using the rotary tool 4 will be described. As shown in FIG. 1, the resin member 2 is placed on a part of the metal member 3 in a state where the metal member 3 is supported from the back side surface 3 b. The pressing jig 5 holds the outer peripheral edge peripheral portion 2e located in the vicinity of the outer peripheral edge 2d of the overlapping region 2c in the resin member 2 in the direction from the resin member 2 toward the metal member 3, so that the resin member 2 and the metal member 3 are held together. Hold. At this time, a distance D1 between the outer peripheral edge 2d of the resin member 2 and the outer peripheral edge 5a of the pressing jig 5 (hereinafter referred to as “jig distance”) is set within a predetermined range. Next, the probe portion 4 b is pressed against the front side surface 3 a of the metal member 3 so that the rotation axis 4 c of the rotary tool 4 is oriented in the direction from the resin member 2 toward the metal member 3. The rotating tool 4 is moved along the outer peripheral edge 2d of the resin member 2 on the front side surface 3a of the metal member 3 while rotating the shoulder portion 4a and the probe portion 4b of the rotating tool 4 about the rotation axis 4c. When the rotary tool 4 is pressed and moved, the distance D2 between the outer peripheral edge 2d of the overlapping region 2c of the resin member 2 and the outer periphery of the shoulder portion 4a of the rotary tool 4 (hereinafter referred to as “tool distance”) D2 is a predetermined range. Within. By such movement of the rotary tool 4, the overlapping region 2 c of the resin member 2 and the overlapping region 3 c of the metal member 3 are melted, and as a result, the resin member 2 and the metal member 3 are joined. Furthermore, the burr 3d protrudes from the front side surface 3a of the overlapping region 3c of the metal member 3 by the movement of the rotary tool 4, and the burr 3d bites into the overlapping region 2c of the resin member 2, and as a result, the resin member 2 and the metal The member 3 is further strongly bonded.

  Here, the range of the jig distance D1 is preferably as small as possible. The overlapping region 2 c of the resin member 2 is reliably pressed against the overlapping region 3 c of the metal member 3, and the bonding strength between the resin member 2 and the metal member 3 can be sufficiently ensured. The range of the tool distance D2 is preferably larger than 0 mm and not larger than 10 mm. While the contact between the outer peripheral edge 2d of the resin member 2 and the shoulder 4a of the rotary tool 4 can be prevented, the overlapping region 2c of the resin member 2 and the overlapping region 3c of the metal member 3 are reliably melted, A sufficient bonding strength between the resin member 2 and the metal member 3 can be secured. Furthermore, the range of the tool distance D2 is preferably greater than 0 mm and 4 mm or less. While the contact between the outer peripheral edge 2d of the resin member 2 and the shoulder portion 4a of the rotary tool 4 can be prevented, the burr 3d generated in the metal member 3 bites into the overlapping region 2c in the resin member 2, and the resin member 2 The bonding strength between 2 and the metal member 3 can be increased. In addition, the tool trace 3e is formed in the passage path of the rotary tool 4 on the front side surface 3a of the metal member 3, and the outer peripheral edge of the tool trace 3e corresponds to the passage path on the outer periphery of the shoulder portion 4a.

  As described above, according to the joining method according to the present embodiment, the location where the resin member 2 is pressed to hold the resin member 2 and the metal member 3 and the location where the rotary tool 4 is pressed are arranged apart from each other. Therefore, the load acting on the resin member 2 can be reduced so as to promote the deformation of the resin member 2. As a result, the deformation of the resin member 2 and the deformation of the metal member 3 due to the deformation can be prevented, the occurrence of poor appearance of the resin member 2 and the metal member 3 can be prevented, and the resin member 2 and the metal member 3 Breakage can be prevented. Moreover, since a joining part can be formed in the area | region where the back side surface 2b of the resin member 2 and the front side surface 3a of the metal member 3 overlap, for example, the amount of heat generated when the shoulder portion 4a of the rotary tool 4 is rotated is increased. By doing so, the area of the joint can be sufficiently secured. Therefore, the bonding strength between the resin member 2 and the metal member 3 can be sufficiently ensured.

  According to the joining method according to the present embodiment, the range of the tool distance D2 is larger than 0 mm and smaller than 10 mm, and preferably the range of the tool distance D2 is larger than 0 mm and 4 mm or less. Therefore, the overlapping region 2 of the resin member 2 and the overlapping region 3c of the metal member 3 are reliably melted by the rotation of the shoulder portion 4a, so that the resin member 2 and the metal member 3 can be reliably bonded. Furthermore, the area of the joint portion can be sufficiently secured, and the joint strength between the resin member 2 and the metal member 3 can be sufficiently secured.

  According to the joining method according to the present embodiment, the range of the tool distance D2 is further determined such that the burr 3d generated in the metal member 3 by the rotation of the shoulder portion 4a bites into the overlapping region 2c of the resin member 2. Therefore, the resin member 2 and the metal member 3 are firmly bonded by the burr 3d generated in the metal member 3, and the bonding strength between the resin member 2 and the metal member 3 can be sufficiently secured.

  Further, according to the joined body 1 according to the present embodiment, the appearance failure of the resin member 2 and the metal member 3 is prevented, the occurrence of breakage of the resin member 2 and the metal member 3 is prevented, and the resin member 2 and Sufficient bonding strength with the metal member 3 can be ensured.

  Although the embodiments of the present invention have been described so far, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention.

  Examples 1 to 12 of the present invention will be described.

[Example 1]
In Example 1, the bonded body 1 is produced under the following conditions using the bonding method according to the present embodiment. The resin member 2 used for the joined body 1 is made of PA (polyamide) resin, and the thickness of the resin member 2 is 3.0 mm. The metal member 3 used for the joined body 1 is made of 5052-H34 aluminum, and the thickness of the metal member 3 is 4.0 mm. In such a joining process of the resin member 2 and the metal member 3, the rotation speed of the shoulder portion 4a and the probe portion 4b of the rotary tool 4 is set to 1300 rpm. The insertion speed for inserting the probe portion 4b of the rotary tool 4 while pressing it against the metal member 3 is 20 mm / min. Immediately after inserting the probe part 4b into the metal member 3, the post-insertion holding time held at a fixed location is 1 sec (seconds). The moving speed of the rotary tool 4 is set to 200 mm / min. The post-movement holding time held at a fixed position after moving the probe unit 4b is 1 sec (seconds). Furthermore, the jig distance D1 is set to 0 mm, and the tool distance D2 is set to 0.1 mm. A joint strength test is performed on the joined body 1 manufactured under such conditions, and the joint strength (joint strength) S of the joined body 1 is measured.

[Example 2]
In Example 2, the bonded body 1 is manufactured under the following conditions using the bonding method according to the present embodiment. The jig distance D1 is 5 mm and the tool distance D2 is 0.1 mm. Conditions other than the jig distance D1 and the tool distance D2 are the same as those in the first embodiment. A joint strength test is performed on the joined body 1 manufactured under such conditions, and the joint strength (joint strength) S of the joined body 1 is measured.

[Example 3]
In Example 3, the bonded body 1 is manufactured under the following conditions using the bonding method according to the present embodiment. The jig distance D1 is 10 mm, and the tool distance D2 is 0.1 mm. Conditions other than the jig distance D1 and the tool distance D2 are the same as those in the first embodiment. A joint strength test is performed on the joined body 1 manufactured under such conditions, and the joint strength (joint strength) S of the joined body 1 is measured.

[Example 4]
In Example 4, the bonded body 1 is manufactured under the following conditions using the bonding method according to the present embodiment. The jig distance D1 is 15 mm, and the tool distance D2 is 0.1 mm. Conditions other than the jig distance D1 and the tool distance D2 are the same as those in the first embodiment. A joint strength test is performed on the joined body 1 manufactured under such conditions, and the joint strength (joint strength) S of the joined body 1 is measured.

[Example 5]
In Example 5, the bonded body 1 is produced under the following conditions using the bonding method according to the present embodiment. The jig distance D1 is set to 0 mm, and the tool distance D2 is set to 2 mm. Conditions other than the jig distance D1 and the tool distance D2 are the same as those in the first embodiment. A joint strength test is performed on the joined body 1 manufactured under such conditions, and the joint strength (joint strength) S of the joined body 1 is measured.

[Example 6]
In Example 6, the bonded body 1 is manufactured under the following conditions using the bonding method according to the present embodiment. The jig distance D1 is set to 0 mm, and the tool distance D2 is set to 4 mm. Conditions other than the jig distance D1 and the tool distance D2 are the same as those in the first embodiment. A joint strength test is performed on the joined body 1 manufactured under such conditions, and the joint strength (joint strength) S of the joined body 1 is measured.

[Example 7]
In Example 7, the joined body 1 is produced under the following conditions using the joining method according to the present embodiment. The jig distance D1 is set to 0 mm, and the tool distance D2 is set to 6 mm. Conditions other than the jig distance D1 and the tool distance D2 are the same as those in the first embodiment. A joint strength test is performed on the joined body 1 manufactured under such conditions, and the joint strength (joint strength) S of the joined body 1 is measured.

[Example 8]
In Example 8, the bonded body 1 is manufactured under the following conditions using the bonding method according to the present embodiment. The jig distance D1 is set to 0 mm, and the tool distance D2 is set to 8 mm. Conditions other than the jig distance D1 and the tool distance D2 are the same as those in the first embodiment. A joint strength test is performed on the joined body 1 manufactured under such conditions, and the joint strength (joint strength) S of the joined body 1 is measured.

[Example 9]
In Example 9, the joined body 1 is produced under the following conditions using the joining method according to the present embodiment. The jig distance D1 is set to 0 mm, and the tool distance D2 is set to 9 mm. Conditions other than the jig distance D1 and the tool distance D2 are the same as those in the first embodiment. A joint strength test is performed on the joined body 1 manufactured under such conditions, and the joint strength (joint strength) S of the joined body 1 is measured.

[Example 10]
In Example 10, the bonded body 1 is manufactured under the following conditions using the bonding method according to the present embodiment. The jig distance D1 is set to 0 mm, and the tool distance D2 is set to 10 mm. Conditions other than the jig distance D1 and the tool distance D2 are the same as those in the first embodiment. A joint strength test is performed on the joined body 1 manufactured under such conditions, and the joint strength (joint strength) S of the joined body 1 is measured.

[Example 11]
In Example 11, the joined body 1 is produced under the following conditions using the joining method according to the present embodiment. The jig distance D1 is set to 0 mm, and the tool distance D2 is set to 1 mm. Conditions other than the jig distance D1 and the tool distance D2 are the same as those in the first embodiment. A joint strength test is performed on the joined body 1 manufactured under such conditions, and the joint strength (joint strength) S of the joined body 1 is measured.

[Example 12]
In Example 12, the bonded body 1 is manufactured under the following conditions using the bonding method according to the present embodiment. As shown in FIG. 4, a metal contact prevention jig 6 is disposed between the outer peripheral edge 2 d of the overlapping region 2 c of the resin member 2 and the shoulder portion 4 a of the rotary tool 4. Conditions other than the arrangement of the contact prevention jig are the same as those in Example 11. A joint strength test is performed on the joined body 1 manufactured under such conditions, and the joint strength (joint strength) S of the joined body 1 is measured.

  Here, in Examples 1 to 4 where the tool distances D2 are equal to each other (= 0.1 mm), the relationship between the jig distance D1 and the bonding strength S is shown in Table 1 below.

  Referring to Table 1, the bonding strength S of Example 1 where the jig distance D1 is 0 mm is 30 N / mm. The joint strength S of Example 2 in which the jig distance D1 is 5 mm is 22 N / mm. The bonding strength S of Example 3 in which the jig distance D1 is 10 mm is 18 N / mm. The joint strength S of Example 4 in which the jig distance D1 is 15 mm is 15 N / mm. Therefore, it can be confirmed that the bonding strength S is increased by reducing the jig distance D1 as much as possible.

  Table 2 below shows the relationship between the tool distance D2 and the bonding strength S in Example 1 and Examples 5 to 10 in which the jig distance D1 is equal to 0 mm (= 0 mm).

  Referring to Table 2, the joining strength S of Example 1 with a tool distance D2 of 0.1 mm is 30 N / mm. The joining strength S of Example 5 with the tool distance D2 being 2 mm is 21 N / mm. The joining strength S of Example 6 in which the tool distance D2 is 4 mm is 10 N / mm. The joining strength S of Example 7 in which the tool distance D2 is 6 mm is 8 N / mm. The joining strength S of Example 8 in which the tool distance D2 is 8 mm is 7 N / mm. The joining strength S of Example 9 in which the tool distance D2 is 9 mm is 5 N / mm. In Example 10 in which the tool distance D2 is 10 mm, the resin member 2 and the metal member 3 cannot be joined. Therefore, it can be confirmed that the resin member 2 and the metal member 3 can be reliably joined when the range of the tool distance D2 is larger than 0 mm and smaller than 10 mm.

  Moreover, in Example 1, Example 5, and Example 6, it can confirm that the burr | flash 3d generate | occur | produced in the metal member 3 has digged into the resin member 2. FIG. On the other hand, in Example 7 to Example 10, it cannot be confirmed that the burr 3d generated in the metal member 3 bites into the resin member 2. Therefore, when the range of the tool distance D2 is larger than 0 mm and 4 mm or less, it can be confirmed that the burr 3d generated in the metal member 3 bites into the resin member 2.

  Furthermore, the jig distance D1 (= 0 mm) and the tool distance D2 (= 1 mm) of Example 11 and Example 12 are equal to each other, and in the joined body 1 of Example 11, the burrs 3d are biting. On the other hand, in the joined body 1 of Example 12, the burr 3d does not bite due to the influence of the contact prevention jig 6. Table 3 shows the bonding strength S of Examples 11 and 12 as described above.

  Referring to Table 3, the bonding strength S of Example 11 where the burr 3d bite occurred was 26 N / mm. The joining strength S of Example 12 in which the burr 3d does not bite is 12 N / mm. Therefore, it can be confirmed that the bonding strength S is increased as a result of the burr 3d generated in the metal member 3 biting into the resin member 2.

DESCRIPTION OF SYMBOLS 1 Bonding body 2 Resin member 2c Overlapping area | region 2d Outer periphery 2e Outer periphery peripheral part 3 Metal member 3a Front side surface 3c Overlapping area 3d Burr 4 Rotating tool 4a Shoulder part 5 Holding jig D1 Distance (tool distance)
D2 distance (tool distance)

Claims (5)

A joining method for joining a resin member and a metal member using a rotary tool having a cylindrical shoulder portion configured to be rotatable around a longitudinal axis,
Placing the resin member overlying a portion of the metal member;
Pressing a peripheral portion of the outer peripheral edge of the resin member located in an overlapping region of the resin member overlapping with a part of the metal member in a direction from the resin member toward the metal member;
In a state where the distance between the outer periphery of the shoulder portion of the rotary tool and the outer peripheral edge of the resin member that is located on the surface of the metal member is maintained within a predetermined range, the rotary tool is removed from the resin member. Pressing the surface of the metal member in a direction toward the metal member, and rotating the shoulder portion,
The predetermined range is determined such that rotation of the shoulder portion melts each overlapping region of the resin member and the metal member so that the resin member and the metal member are bonded.   The joining method according to claim 1, wherein the predetermined range is larger than 0 mm and smaller than 10 mm.   The joining method according to claim 2, wherein the predetermined range is greater than 0 mm and 4 mm or less.   2. The joining method according to claim 1, wherein the predetermined range is further determined such that a burr generated in the metal member by the rotation of the shoulder portion bites into an overlapping region of the resin member.   The joined body produced by joining the said resin member and the said metal member using the joining method as described in any one of Claims 1-4.