JP5843103B2 - Die for grid substrate casting of lead storage battery plate - Google Patents

Description

  The present invention relates to a mold for casting a grid substrate used for a lead-acid battery electrode plate, and more particularly to an extrusion pin that extrudes a grid substrate from a mold and releases it.

There are two types of electrode plates for lead-acid batteries: Tudor type, Cladding type, and Paste type. Among them, the paste type electrode plate is often used because of its high productivity and low cost.
This paste type electrode plate (hereinafter referred to as “electrode plate”) is produced by holding a paste-like active material using a lead compound or the like on a lattice substrate cast from lead or a lead alloy, and further aging and drying. Is done. The paste-like active material is held in the lattice region of the lattice substrate.
More specifically, with reference to FIG. 1, the lattice substrate has a lateral bone 2 and a longitudinal bone 3 arranged in a lattice shape inside the frame bone 1 forming the outer periphery, and one side of the frame bone 1. Are provided with ears 4 protruding outward. Then, the grid-like region of the grid substrate is filled with a paste-like active material and held. In FIG. 1, protrusions having the same shape as the ears 4 are also provided on the side opposite to the side on which the ears 4 are provided. This part is a lattice substrate (electrode plate) in the lead acid battery manufacturing process. ) In order to improve the handleability, and is removed at an appropriate stage. Moreover, the leg part 5 is protruded and provided in the edge | side facing the edge | side in which the ear | edge part 4 was provided as needed.

  In the casting of the lattice substrate, lead or a lead alloy is melted and poured into a casting cavity formed by combining a movable mold and a fixed mold, and the molten metal is cooled and solidified. Thereafter, the movable mold is released from the fixed mold, and the lattice substrate on the fixed mold side is released from the fixed mold by extruding it using an extrusion pin disposed on the fixed mold (Patent Document 1: Japanese Utility Model Publication No. 63-3737). Issue gazette). Patent Document 1 does not clearly disclose how the extrusion pins are arranged in the lattice region of the lattice substrate.

Japanese Utility Model Publication No. 63-3736

  In the region of the intersection portion 6 of the horizontal bone 2 and the vertical bone 3 of the lattice substrate described with reference to FIG. 1, the amount of lead is larger than the linear portion of the horizontal bone 2 or the vertical bone 3 extending from the intersection portion. It takes a longer time for cooling (solidification of molten lead) than for this part. If the grid substrate is released from the fixed mold without waiting for its sufficient solidification, sufficient volume shrinkage due to cooling is not completed at the intersection, so the contact surface of the extrusion pin used to the grid substrate Depending on the shape and the position of the push pin, the lattice substrate may be deformed due to a problem such as the lattice substrate being caught on the fixed mold.

  If the fixed mold is caught when the lattice substrate is released, “close the mold”-“inject molten lead or lead alloy”-“solidify”-“open the mold”-“release the lattice substrate This greatly affects the productivity of the grid substrate that repeats casting by determining the time of each process.

  The problem to be solved by the present invention is to provide a mold capable of smoothly releasing a grid substrate from a fixed mold, reducing deformation of the grid substrate at the time of mold release, and casting the grid substrate with high productivity. Is to provide.

  In order to solve the above problems, a mold for casting a lattice substrate of a lead storage battery electrode plate according to the present invention has the following configuration.

A movable mold and a fixed mold constituting the casting cavity are provided, and extrusion pins for the lattice substrate to be cast are arranged at predetermined positions of the fixed mold. The push pin has a contact surface that directly contacts the lattice substrate and a support column that supports the contact surface, and is disposed so as to be located immediately below the intersection of the horizontal and vertical bones of the lattice substrate. Then, the abutment surface, characterized by having abutting wide part of the lateral bone and vertical bone extending the lateral bone and vertical bone intersections region from the intersections region.

In the above, in the casting mold, the casting cavity for the transverse bone and the casting cavity for the longitudinal bone have the cavity for the thick bone and the cavity for the thin bone, respectively. in that it is arranged at least one cavity for fine aggregate. In addition , at the intersection of the horizontal bone and the vertical bone where the push pin is arranged, at least one of the horizontal bone and the vertical bone is necessarily a thick bone (Claim 1 ).

When providing a cavity for Futoshihone, one for casting cavity for casting cavity and Tatekotsu for horizontal bone, with a cavity for Futoshihone arranged to bias the predetermined area of the grating substrate, said the installation density of extrusion pins arranged in biased allowed region is preferably higher than the other areas (claim 2). Moreover, it is preferable that the contact surface of the extrusion pin has a planar shape.

  In the present invention, in order to release the lattice substrate, the abutment surface of the extrusion pin that directly contacts the lattice substrate is not limited to the intersection portion region of the transverse bone and the longitudinal bone, but also the transverse bone and the longitudinal bone extending from this intersection portion. Therefore, it is possible to prevent the pushing force from concentrating on a narrow portion of the lattice substrate, and to contribute to the prevention of deformation of the horizontal and vertical bones of the lattice substrate.

When a lattice substrate is cast using the casting mold according to claim 1 , the lattice substrate has thick and thin bones in the transverse bone and the longitudinal bone, respectively, and at least one fine bone between the thick bones. Will be placed. When such a lattice substrate is filled with a paste-like active material, the paste-like active material wraps around from the side of the fine bone portion to the back side of the filling surface, and an electrode plate that is sufficiently filled with the active material on both the front and back surfaces can be produced. it can. In a casting mold for casting such a lattice substrate, if at least one of the transverse bone and longitudinal bone at the intersection of the transverse bone and longitudinal bone where the push pin is arranged is always a thick bone, Compared to the case where the push pin is placed directly under the intersection of the horizontal bone and the vertical bone of the thin bone, the area of the intersection portion area is widened, and the force of the push pin is dispersed to easily suppress deformation of the lattice substrate. Can be released.
Furthermore, when one of the casting cavity for the horizontal bone and the casting cavity for the vertical bone is disposed with the thick bone cavity being biased to a predetermined region of the lattice substrate, the lead in the biased region is disposed. Since the volume is increased and the volume shrinkage due to the cooling is delayed, it is possible to ensure the release of the lattice substrate by making the installation density of the extrusion pins in the biased area higher than the other areas. .

It is a top view which shows the positional relationship of the intersection part of the crossbone of a lattice board | substrate and a longitudinal bone, and an extrusion pin about the lattice board | substrate cast with the conventional casting die. In the casting mold of this invention, it is the elements on larger scale which show the positional relationship of the intersection of the horizontal bone and the vertical bone of the lattice board | substrate cast, and an extrusion pin. It is a top view which shows the lattice board | substrate cast with the casting die of Example 1 of this invention with the positional relationship with an extrusion pin. It is a top view which shows the lattice board | substrate cast with the casting die of Example 2 of this invention with the positional relationship with an extrusion pin. It is a top view which shows the lattice board | substrate cast with the casting die of Example 3 of this invention with the positional relationship with an extrusion pin. It is a top view which shows the lattice board | substrate cast with the casting die of Example 4 of this invention with the positional relationship with an extrusion pin. It is a top view which shows the lattice board | substrate cast with the casting die of Example 5 of this invention with the positional relationship with an extrusion pin.

<Movable type>
The movable mold described in the present invention is a type that opens and closes with respect to the fixed mold, which will be described later, and forms a casting cavity when the fixed mold is closed to cast the lattice substrate. If it is in a position to open the fixed mold away from the fixed mold, the lattice substrate is released from the fixed mold.
The movable type material is not particularly limited, but heat resistance higher than the temperature of the molten lead alloy is required because the molten lead alloy is poured into the casting cavity.

<Fixed type>
The fixed mold described in the present invention constitutes a casting cavity in a pair with the aforementioned movable mold. In order to open the movable mold and release the cast lattice substrate from the fixed mold, an extrusion pin, which will be described later, is installed on the fixed mold so as to protrude into the casting cavity.
Since it is desirable that the fixed mold behave in the same manner as the movable mold, the material is preferably the same as that of the movable mold.

<Lattice substrate>
The lattice substrate cast by the casting mold of the present invention has a frame bone that constitutes the outer edge, and a lateral bone and a longitudinal bone that constitute the lattice-like region formed inside the frame bone.
The number of horizontal bones and vertical bones is not particularly limited, but a plurality of horizontal bones and vertical bones are provided because they are to retain active materials later. It is preferable to arrange the bones so as to have at least one fine bone between the thick bones. By doing so, when the lattice-like substrate is filled and held later with the paste-like active material, the paste-like active material easily goes around from the side of the fine bone portion to the back side of the filling surface.
When one of the casting cavity for the transverse bone and the casting cavity for the longitudinal bone is arranged with the thick bone cavity biased to a predetermined area of the lattice substrate (for example, for the thick bone for the thick transverse bone) When the cavity is arranged biased to a predetermined area of the lattice substrate), the side between the side provided with the ear part and the side facing this is divided into two at the center, and the side side provided with the ear part is opposed to this. In the region on the side, increase the number of thick horizontal bones in the latter region. More specifically, the ratio is preferably 1: 1.3 to 1: 1.8.
Ears protruding outward are provided on one side of the frame of the lattice substrate, and these ears function as a current collector. In addition, by providing a protruding part having the same shape as the ear part on the side opposite to the side of the frame bone provided with the ear part, the lattice substrate (electrode plate) in the lead acid battery manufacturing process is formed by the ear part and the protruding part. It can be supported and hung, and handleability can be improved.

<Casting of lattice substrate>
The lattice substrate to be cast is made of lead or a lead alloy, and Sn, Ca, Sb or the like can be used as an alloy component, and among these, it is preferable to use both Sn and Ca. When Ca is added, the strength of the lattice substrate can be maintained and self-discharge of the lead storage battery can be reduced. The phenomenon that the corrosion of the lattice substrate easily occurs when Ca is added can be suppressed by the addition of Sn.
The temperature control when casting the lattice substrate is as follows: a lead valve for supplying molten lead and a heater for pouring molten lead into the casting mold are set to 280 ° C to 500 ° C, and a heater for the casting mold is set to 180 ° C to 200 ° C. It is preferable that
The time from pouring molten lead into the casting mold to cooling and solidification is preferably 8.5 to 20 seconds. However, depending on the size, thickness and design of the lattice substrate to be cast, Since the hot water flow differs, the time until cooling and solidification is appropriately optimized.

<Extruded pin>
The extrusion pin arranged in the fixed mold is used when the cast lattice substrate is released from the fixed mold. The extrusion pin is configured by a contact surface that is in direct contact with the cast lattice substrate and a column that supports the contact surface.
The material of the extrusion pin is not particularly limited. However, since the extrusion pin comes into contact with the molten lead alloy poured into the casting cavity, heat resistance higher than the temperature of the molten lead alloy is required.

As shown in FIG. 2, the push pin is arranged such that when the push pin 7 is pushed out, the contact surface at the tip of the pin becomes the region of the intersection 6 of the transverse bone 2 and the longitudinal bone 3. The pushing pins 7 do not have to be arranged corresponding to the intersections of all the horizontal bones 2 and the vertical bones 3, and the number of the pushing pins 7 is appropriately determined according to the size and mass of the lattice substrate. More specifically, it is preferable that one extrusion pin is provided so as to bear a lattice substrate area of 3850 to 4500 mm ² . By arranging the extrusion pins at such a ratio, it is possible to prevent the lattice substrate from being caught on the fixed die and the lattice substrate from being deformed while suppressing the cost of the casting mold.
As described above, the distance between the side of the frame bone provided with the ear part and the side facing this is divided into two at the center, and the latter side is divided into the side side area provided with the ear part and the side side side facing this. The arrangement number of thick horizontal bones is biased in the area (for example, when the arrangement ratio of thick horizontal bones is 1: 1.3 to 1: 1.8, the installation density of the push pins is 1: 1 between both areas. .5 to 1: 3.0) and the side of the latter region (side opposite to the side of the frame bone provided with the ears) are provided with legs, so when releasing the lattice, It is possible to prevent the leg from being caught by the fixed mold.
The shape of the extrusion pin is not particularly limited as long as it can extrude the lattice substrate from the fixed mold, but the column portion is preferably a columnar or polygonal column, and is circular for ease of manufacture. A columnar one is particularly preferable. The push-out amount of the push-out pin is not particularly limited, but the push-out speed is preferably the same for all push-out pins, and in this way, local concentration of push-out force is prevented. Therefore, deformation at the time of releasing the lattice substrate can be further reduced.

<Extrusion pin tip>
The tip of the extrusion pin is a contact surface that directly contacts the lattice substrate, and may be the same material as the column of the extrusion pin or a different material. In the case of a different material, the material is not particularly limited, but a material having heat resistance sufficient to withstand the temperature of molten lead.
The size of the abutting surface is larger than the intersecting point portion to be abutted, and at the time of abutting, the abutting surface has a size that abuts on the intersecting portion and a part of the horizontal bone and the longitudinal bone extending from the intersecting portion region.
The shape of the abutting surface is not particularly limited, and a cross-shaped groove provided on the plane so as to receive the intersection portion, a planar shape that can be easily separated from the intersection portion, etc. should be used. However, it is preferable to have a planar shape for ease of manufacturing the extrusion pin.

Embodiments of the present invention will be described below with reference to the drawings.
A lead alloy containing Sn: 1.0 to 1.8% by mass and Ca: 0.5 to 1.0% by mass was melted, and the casting molds of Examples 1 to 5 and Comparative Example 1 below were used. Then, the lattice substrate was cast by the gravity casting method. The electric heater for the valve through which molten lead passes and the container for storing the molten lead are set to 480 ° C. to 500 ° C., and the movable and fixed electric heaters are set to 180 ° C. to 200 ° C.

Example 1
Movable molds and fixed molds were produced using ductile cast iron (containing graphite in a spherical shape). The movable mold is connected to the fixed mold by two support columns and can be freely opened and closed with respect to the fixed mold. A mold release agent (mixed liquid in which cork powder is mixed with water) is sprayed onto the movable mold and the stationary mold, and a molten lead alloy is poured into the mold to cast a lattice substrate. When the predetermined time (15 seconds) has passed, the movable mold is opened, and the extrusion pin protrudes to release the lattice substrate from the fixed mold. The push pins all move at the same timing and the same protruding speed, and the maximum protruding amount is 8 to 11 mm from the inner surface of the fixed mold.

In this mold for casting a lattice substrate, a casting cavity for a horizontal bone and a casting cavity for a longitudinal bone each have a cavity for a thick bone and a cavity for a fine bone, and the lattice substrate shown in FIG. 3 is cast. The In other words, this lattice substrate has a length of 140 mm, a width of 385 mm, and a thickness of 6.3 mm, and a relatively thick bone and a thin bone are arranged on each of the horizontal bone 2 and the vertical bone 3. Specifically, thick transverse bones 2-1 to 2-5 are arranged, and between the side of the frame bone 1 provided with the ear part 4 and the thick transverse bone 2-1, between the thick transverse bones 2-1 and 2 4 and between the thick transverse bones 2-2 and 2-3, four thin transverse bones are arranged, respectively, between the thick transverse bones 2-3 and 2-4, and the thick transverse bone 2-4. 3-5 and between the side opposite to the side of the frame bone provided with the thick horizontal bone 2-5 and the ear part 4, three thin horizontal bones are arranged. Four thick vertical bones are arranged, and one thin vertical bone is arranged between the thick vertical bones and between the thick vertical bones and the sides of the frame bones.
In the fixed mold, 14 extrusion pins are arranged, and the arrangement is shown as “position of the extrusion pins” on the lattice substrate of FIG. 3 for convenience. The push pin is arranged at the intersection of the thick horizontal bone and the thin vertical bone, and the contact surface with the lattice substrate is a circular plane. The area of this plane (28
mm ²⁾ is larger than the area of the intersections of the area (16 mm ^2). Note that the area of the intersection is regarded as a quadrangle as shown in FIG. 2, and is defined as the width of the horizontal bone × the width of the vertical bone.
Also, divide the side of the frame bone provided with the ears and the side opposite to it in the middle, and place a thick horizontal bone between the side of the side provided with the ears and the side of the side facing this The number is 1: 1.5. This indicates that the thick horizontal bone is biased to the region on the side facing the side of the frame bone provided with the ear portion, and the interval between the thick horizontal bones is narrowed. Since the push pin is arranged at the intersection of the thick horizontal bone and the thin vertical bone, the ratio of the number of the thick horizontal bones and the ratio of the number of the push pins are the same. And, the area of the lattice substrate that one push pin bears is
3850 mm ² .

Example 2
A grid substrate casting mold similar to that of Example 1 was used except that the number of extrusion pins was 12 and the arrangement thereof was as shown in FIG. In this example, the arrangement of the vertical and horizontal bones of the lattice substrate is the same as in Example 1. However, the push pin is divided in half between the side of the frame bone provided with the ears and the side opposite thereto. In addition, the arrangement number is the same in the region on the side where the ears are provided and the region on the side opposite to the region. Then, the area of the grating substrate per one ejector pin will bear is 4492mm ^2.

(Example 3)
The grid substrate casting mold was the same as in Example 1 except that the number of extrusion pins was 10 and the arrangement was as shown in FIG. In this example, the arrangement of the vertical and horizontal bones of the lattice substrate is the same as in Example 1. However, the push pin is divided in half between the side of the frame bone provided with the ears and the side opposite thereto. In addition, the number of arrangement is set to 1: 0.7 in the region on the side where the ears are provided and the region on the side opposite to the region. Then, the area of the grating substrate per one ejector pin will bear is 5390mm ^2.

Example 4
A grid substrate casting mold similar to that of Example 1 was used except that the number of extrusion pins was 14 and the arrangement thereof was as shown in FIG. In this example, the arrangement of the vertical and horizontal bones of the lattice substrate is the same as in Example 1. However, the push pin is divided in half between the side of the frame bone provided with the ears and the side opposite thereto. In addition, the number of arrangements was set to 1: 2.5 in the region on the side where the ears were provided and the region on the side opposite to the region.

Example 5
A grid substrate casting mold similar to that of Example 1 was used except that the number of extrusion pins was 14 and the arrangement thereof was as shown in FIG. In this example, the arrangement of the vertical and horizontal bones of the lattice substrate is the same as in Example 1. However, the push pin is divided in half between the side of the frame bone provided with the ears and the side opposite thereto. In addition, the number of arrangements was set to 1: 6 in the region on the side where the ears were provided and the region on the side opposite to the region.

Comparative Example 1
The lattice substrate similar to that of Example 1 except that the area (12 mm ² ) of the contact surface of the extrusion pin with the lattice substrate is smaller than the area (16 mm ² ) of the intersection of the thick horizontal bone and the thin vertical bone. A casting mold was obtained.

  In each of the above embodiments, the contact surface of the push pin to the lattice substrate is circular, and the area thereof is larger than the area of the intersection portion of the thick horizontal bone and the thin vertical bone. In addition, a thin film was stretched between the thick horizontal bones and the thin vertical bones. That is, the circular shape of the contact surface protrudes from the region of the intersection and remains on the cast lattice substrate. On the other hand, in Comparative Example 1, such a film is not formed.

Table 1 shows the results of the evaluation of the number of hooks and the deformation amount of the lattice substrate when the lattice substrate is released from the fixed die in the casting of the lattice substrate using the molds of the above examples and comparative examples.
As for the number of catches, the number of catches on the fixed mold without being able to release the grid substrate was counted when 1000 faces of the grid substrate were cast. This number includes cases where the mold could be released, but once caught on the fixed mold and could not be released smoothly.
The amount of deformation is determined by extracting the lattice substrate as a sample every 10-side casting, placing this on the flat base, with the contact surface side of the push pin down, and setting the height of the contact point of the push pin from the flat stand. Measured and compared with the portion where the push pin is not in contact, the difference in the raised height was defined as the amount of deformation. The average amount of deformation is
0 mm ≤ deformation ≤ 1 mm: "Small"
1mm <deformation amount ≤ 2mm: "Medium"
2 mm <deformation amount ≤ 3 mm: "Large"
3 mm <Deformation amount: “Extra large”
As a result, the amount of deformation was evaluated.

  From the results of Table 1, there was a tendency that the magnitude of deformation was in the order of Example 3> Example 2> Example 1. Further, when Examples 1, 4 and 5 were compared, the amount of deformation of Example 5 was large, and Examples 1 and 4 were equally small. However, when the number of catches was compared, Example 1 had more and the legs 5 had more catches.

From the above results, if the number of push-out pins is small, the deformation becomes large at the time of mold release, and if the deviation in the ratio of the pin installation density is small, the catch on the leg side increases. On the other hand, if the deviation of the ratio of the installation density is large, the ear side is frequently caught.
In the above embodiment, one extrusion pin bears the area of the lattice substrate of 3850 to 4500 mm ² , and bisects between the side of the frame bone provided with the ear part and the side opposite to this at the center, It was confirmed that it is preferable to set the number of push pins to be in a ratio of 1: 1.5 to 1: 3.0 in the region on the side where the ears are provided and the region on the side opposite to the region.

  In Comparative Example 1, although the lattice substrate on which the extrusion pins were cast was extruded from the fixed mold, it could not be reliably removed from the fixed mold, and the casting operation could not be performed continuously. Further, as a result of visually confirming the amount of deformation, it was greatly deformed, and the intersection where the push pin contacts was particularly greatly deformed.

DESCRIPTION OF SYMBOLS 1 ... Frame bone, 2 ... Horizontal bone, 3 ... Vertical bone, 4 ... Ear part, 5 ... Leg part, 6 ... Intersection part, 7 ... Extrusion pin

Claims (3)

A mold for casting a grid substrate of a lead storage battery electrode plate, comprising a movable mold and a fixed mold constituting a casting cavity, and an extrusion pin of the grid substrate to be cast is disposed at a predetermined position of the fixed mold. ,
The casting cavity for the transverse bone and the casting cavity for the longitudinal bone each have a thick bone cavity and a fine bone cavity, and there is at least one fine bone cavity between the thick bone cavities. Arranged,
Said extrusion pin, the abutment surface in direct contact with the grid substrate, and a support column for supporting the contact surface, just below the intersection portion of the lateral bone and vertical bone grating substrate, the intersection portion, and the lateral bone Arranged so that at least one of the longitudinal bones is always located in the thick bone ,
The lead-acid battery electrode plate, wherein the contact surface has an intersection part area of the transverse bone and the longitudinal bone, and an area contacting the part of the transverse bone and the longitudinal bone extending from the intersection part area. Die for casting lattice substrates. For one of the casting cavity for the transverse bone and the casting cavity for the longitudinal bone, the cavity for the thick bone is arranged so as to be biased to a predetermined area of the lattice substrate, and the installation density of the push pins arranged in the biased area is arranged. 2. The mold for casting a lattice substrate according to claim 1, wherein the height is set higher than that of other regions. The mold for casting a lattice substrate according to claim 1 or 2 , wherein the contact surface of the extrusion pin has a planar shape.

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