JPH0329533B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application: The present invention provides a method for manufacturing micro pin fins that enables heat exchangers such as air conditioners to be made thinner and dramatically improves heat exchange efficiency. This relates to processing tools for manufacturing.

Background of the Invention: A heat exchanger used in a heating device or a cooling device is provided with protruding fins for heat absorption or heat radiation.
The fins are generally of the continuous plate-like louver type, but for heat exchangers installed in small locations, the pin type is often used.

Pin fins have excellent heat exchange efficiency, but in order to increase this efficiency, for example, the cross section should be 0.5
It is necessary to form ultra-fine pins of about 0.5 mm or less at a density of about 200 pins ^per cm2 or more, and in order to increase the flow rate of the heat exchange medium in contact with the fins and increase the amount of passing through. The above-mentioned micropin group must be arranged as micropin fins according to a certain standard.

Conventional technology: There are two methods for forming such micro pin fins: (a) Formation by mechanical processing method (cutting or similar method, plastic processing), (b) Planting by brazing or adhesive. has become the mainstream.

Regarding (a), a cutting method using a cutting tool has been proposed, as seen in Japanese Patent Publication No. 54-11548, for example. That is, the cut piece is made to stand up by the cutting angle of the cutting tool, and is left uncut to form a pin fin. However, with this method, the pitch of the pin fins is 1 mm in the longitudinal direction of the heat exchanger and 3 mm in the direction perpendicular to this.
There was a limit to the degree of heat exchange, and it was impossible to form microscopic pin fins that were extremely fine and arranged at an extremely small pitch, which was necessary to improve heat exchange efficiency.

Additionally, grooves are carved in the longitudinal direction and transverse direction of the heat exchanger using a groove processing tool such as a side cutter or a metal saw, thereby creating a group of pins to be arranged. However, although it is possible to make the thickness of each pin or the pitch interval finer as desired by this means, it is extremely difficult to form pin fins with high efficiency.

Problems to be solved: Pin fins formed by conventional techniques do not have an orderly pin shape or a fine pin arrangement density, and a micro pin fin with excellent heat exchange efficiency cannot be obtained. Alternatively, it has been impossible to form micro pin fins at an industrially effective efficiency. In other words, in the method of cutting a material with parallel grooves using a cutting tool to make a section stand up to form a pin fin, if the pin fin dimension is below the above limit, the section (pin fin) will curl, break, or fall. An orderly finish cannot be obtained. Furthermore, the fin shape that is formed is greatly influenced by the state of the cutting edge of the cutting tool, so when using a multi-bit tool, individual differences between individual tools will be noticeable in the machining state, and the fin shape that will be formed will be It was difficult to stabilize it.

Cutting with a multi-bite requires rotating a large-diameter disk equipped with multiple bits, but it is difficult to increase the rotation speed from the viewpoint of rotational balance, etc., and there is a limit to the efficiency of forming pin fins. In addition, with the method of forming pin fins by cutting grooves in two directions that intersect with each other using a conventional tool such as a metal saw, the movement of the workpiece or cutter is an intermittent movement, making it inefficient to form fine pin fins. It was bad. In all of these cases, the formation of micro pin fins for heat exchangers such as air conditioners required a lot of processing time and was unsuitable.

Means for Solving the Problems: The present invention has been made to solve the above problems, and by carving a fine width groove in a workpiece using a specific processing tool, The aim is to provide a method for producing ultra-fine pins at high density and smoothly forming micro pin fins. Another object of the present invention is to provide a processing device for carving grooves with a fine width. Specifically, a machining tool with a spiral outer blade having a thread lead equal to the pitch in which the pin fins are arranged in the longitudinal direction is used to cut a workpiece in which multiple rows of grooves arranged in parallel in the longitudinal direction are cut in advance. A groove is carved that crosses the existing groove, and the uncut portion of the material is used as a micropin to form a fin.

Effect of the invention: The present invention is a method that uses a specific machining tool, and because it is a pure chip removal method and the material to be cut is mainly made of aluminum alloy, it can perform micro-processing at high speed and with high precision. Pins can be formed.

That is, cutting can be performed at a speed of 1500 m/min or more, and high efficiency conditions such as a cutting amount of 0.01 mm/tooth or more can be achieved. The spiral tool of the present invention can machine one cross groove in one rotation of the tool. Under these conditions, if a spiral tool with an outer diameter of 125 mm is used, it is possible to process micro pin fins at a high efficiency of more than 4000 rows per minute.

Embodiment: Hereinafter, a specific embodiment of the present invention and a processing tool used therein will be described based on the drawings.

For example, the material to be cut 2 is a member forming micro pin fins such as a heat exchanger of an air conditioner, etc.
As shown in FIG. 1 or 2, an appropriate number of longitudinal grooves 3 are cut in parallel thereto. The material of the material to be cut 2 is preferably a material with excellent thermal conductivity, and in this example, an aluminum alloy was used. The plurality of rows of longitudinal grooves 3 can be cut using a conventional thin-blade tool such as a side cutter, metal saw, cutting wheel, or the like.

Next, a cross groove 4 that crosses the longitudinal grooves 3 is cut into the cut material 2 having the plurality of rows of longitudinal grooves 3 using a specific spiral tool 10. When the longitudinal grooves 3 and the cross grooves 4 are carved in this way, the uncut portions at the intersections become micro pins 5, and as shown in FIG. A micro pin fin 1 having an arrangement group of 1 is obtained.

As shown in FIG. 3 or 4, the specific spiral tool 10 used in the manufacturing method of the present invention has a notch 11 having a small central angle at one location of a circular thin plate made of a thin blade material such as hard blade steel. is provided, and this notch 11
The two radii that limit the
It has been established around Furthermore, the intersection point with the outer periphery of one radius that defines the notch portion 11 is defined as a starting portion 14, and the intersection point with the outer periphery of another radius is defined as a completed portion 15. The distance between the rotation center and the completion part 15 is longer than the distance between the rotation center and the start part 14, and in some cases, the reinforcing part 12 is in contact with the radius passing through the completion part 15.
may be provided.

The lead amount 16 of such a spiral tool 10
is set equal to the cutting pitch of the cross groove 4, and the groups of cutting edges 13 provided around the outer periphery are set so that a predetermined depth of cut is given to each cutting edge 13 as the spiral tool 10 rotates. In addition, each cutting edge 13 has a longer distance along the radius from the center of rotation to the tip of the cutting edge than the preceding cutting edge, and protrudes by the same amount as the predetermined depth of cut. In other words, it is shaped like a broach wrapped around the outer periphery of a rotating disk.

Regarding the dimensions of the helical tool 10, in the embodiment illustrated in FIG. is 4 degrees (center angle of notch 11 is 7 degrees), average radius is 60 mm, number of cutting edges 13 is 350, step between adjacent cutting edges (depth of cut of each cutting edge) is 0.012 mm on average, twisted lead Although the amount is 0.6 mm, these values are selected according to the dimensions of the micro pin fin to be processed and are not limited to the above values.

When manufacturing micro pin fins, this spiral tool 10 is attached to a main shaft 17 of a processing machine having an axis in a plane parallel to the workpiece 2 by an appropriate means such as via an attachment part 18. Main shaft 17 at this time
The angle between the cut material 2 and the cut material 2 is determined by the design angle of the cross groove 4 and the longitudinal groove 3. When the main shaft 17 and the workpiece 2 are parallel, the plurality of longitudinal grooves 3 and the cross grooves 4 intersect at almost right angles, as illustrated in FIG. The angle formed by the longitudinal grooves 3 and the cross grooves 4 of the row is approximately equal to the angle of deviation from parallelism, as illustrated in FIG. 9.

The method of the invention is schematically illustrated in FIGS. 5, 6a and 6b, and 7a and 7b. As is clear from these figures, in order to machine the cross groove 41 in one rotation of the helical tool 10, the helical tool 1
The rotation at 0 is performed in synchronization with the relative movement between the helical tool 10 and the workpiece 2, and the helical pitch of the helical tool 10 and the feed amount per tool rotation are set to be equal. This relative movement may be performed by moving the material 2 to be cut while rotating the helical tool 10 in a fixed position, or by securing the material 2 to be cut in a fixed position and moving the material 2 while rotating the spiral tool. . That is, as shown in FIG. 5, the starting part 14 of the helical tool 10 comes into contact with the surface edge of the workpiece 2 and starts cutting the cross groove 4, and at the same time, the center of rotation due to the rotation of the helical tool 10 As the distance between the cutting edge 13 and the cutting edge 13 increases, the cutting edge gradually cuts deeper, and by passing through the completion part 15, a required groove depth is provided and one cross groove 2 is carved. In this way, when the cross grooves 4 of the required depth are carved and the micro pins 5 are formed by the longitudinal grooves 3 and the cross grooves 4, as shown in FIG. 6 or FIG. The starting portion 14 of the helical tool 10, which has a lead amount 16 equal to the cross groove cutting pitch, faces the next cross groove 4 carving position. Thereafter, this process is repeated to form groups of micro pins 5 all over the required area of the workpiece 2, and the desired micro pin fins 1 are obtained.

Further, the spiral tool used in the method of the present invention is a thin-blade side cutter-like tool in which adjacent cutting blades are provided with a predetermined step difference from each other and a large number of cutting blades are provided around the outer periphery, as shown in FIG. 3, for example. Create one by one.
Then, one notch is provided in the radial direction in a region including the maximum and minimum distances from the center of rotation to the tip of the cutting blade. This is clamped and fixed by a pair of flanges with predetermined twist surfaces facing each other, to obtain a helical tool with a predetermined twist.

Effects of the invention: The specific spiral tool used in the method of the present invention uses carbide material (or high grade material) as the tool material,
It is possible to extend the tool life. Further, since no deforming force is applied to the micro pins that are left uncut by the grooves, fine micro pin fins can be stably processed. Furthermore, in the manufacturing method of the present invention, the diameter of the helical tool has a large ratio compared to the width of the micro pin fin forming part, so the local chords on the long circumference converge into an arc, and the micro pin group The base of the micro pin fin becomes substantially flat, and the function of the micro pin fin is not impaired.

The present invention proposes a means for manufacturing micro pin fins with minute dimensions with excellent processing efficiency, and at the same time provides a processing tool for use in this manufacturing means. The resulting micro pinfins can significantly improve the efficiency of various heat exchangers, including those used in air conditioners, and have great industrial applicability.

[Brief explanation of drawings]

Fig. 1 is a plan view of a workpiece with longitudinal grooves carved therein, Fig. 2 is a side view thereof, Fig. 3 is a plan view showing an example of a spiral tool used in the present invention, and Fig. 4 is a plan view thereof. 5 is a perspective explanatory view of one specific example of the method of the present invention, FIGS. 6 a, b, and 7 a, b are schematic explanatory views of the process, and FIGS. It is a top view of the micro pin fin obtained by this invention. 1... Micro pin fin, 2... Material to be cut,
3... Longitudinal groove, 4... Cross groove, 5... Micro pin, 10... Spiral tool, 11... Notch, 12... Reinforcement part, 13... Cutting edge, 14... Starting part, 15... Completed part, 16... Lead amount, 17
...Main shaft, 18...Mounting section.

Claims (1)

[Scope of Claims] 1. A member on which micro pin fins are to be formed is used as a material to be cut, and a plurality of rows of longitudinal grooves are carved in advance using a thin-blade tool, and then a cutting blade is formed around the outer periphery. Using the installed spiral tool, while moving the material to be cut and the spiral tool relatively, the spiral tool is synchronized with this moving speed and continuously so that the spiral pitch and the feed amount per tool rotation are equal. Cross grooves that intersect with the longitudinal grooves are sequentially carved, and the uncut portions of both grooves are used as micro pins.By applying this operation to the required area, the resulting micro pin group is used to form micro pin fins. A method for producing a micro pin fin for a heat exchanger, characterized by forming a micro pin fin for a heat exchanger. 2. Cutting out a part including a small center angle of a thin, almost circular blade material having a mounting part to the main shaft of a processing machine at the center to form a notch part defined by a starting part and a finishing part on the outer periphery. A cutting edge is provided around the outer periphery so that the distance from the center of rotation to the cutting edge becomes progressively longer from the starting part to the finishing part, and the twisted surface of the specified lead faces the notched part. For a heat exchanger characterized by a structure in which the tool is twisted by being compressed by a pair of flanges, and has a lead amount equal to the pitch of the cross groove to be carved in the material to be cut, resulting in a helical tool. A tool for processing micro pin fins.