JP7477668B2 - Drum clamps and drums - Google Patents

Description

The present invention relates to a drum clamp that fastens the top plate to the body of an open drum, and to a drum with the drum clamp attached.

In a steel open drum, the top plate of which is detachable from the can body and which is specified by JIS Z 1600, the can body is filled with the contents, and then the top plate (sometimes called a lid for an open drum) is attached to the can body to close it. After the lid is put on, a band member 1 having a U- or V-shaped cross section as shown in FIG. 8 and constituting a drum can fastening ring 10 is attached to the joint between the can body 6 and the top plate 7 as shown in FIG. 9, and the band member 1 is fastened with a bolt 4 and a nut 5 to fasten the can body 6 and the top plate 7. A packing is usually provided at the joint of the top plate 7, and the packing is deformed by the fastening, preventing leakage of the contents, and can withstand an internal pressure of, for example, about 100 kPa. Therefore, such an open drum 50 can also be used as a drum for internal pressure resistance (for liquid hazardous materials).

Such pressure-resistant drums (for liquid hazardous materials) must meet the criteria for airtightness tests, drop strength tests, water pressure strength tests, and stacking tests set out in the UN Recommendations on the Transport of Dangerous Goods, just as sealed drums do. For example, by using the band member 1 described above, it is possible to meet the criteria.

On the other hand, in the bolt-type fastening ring 10 for drums using the bolts 4 and nuts 5 described above (hereinafter also referred to as "bolt-type fastening ring") 10, the band member 1 is C-shaped with a portion of the circumference cut out, as shown in FIG. 8, and the mounting members 2, 3 for inserting the bolts 4 are welded to both ends of the band member 1. Usually, the mounting members 2, 3 are welded to the band member 1 so that both ends 1a, 1b of the band member 1 coincide with the respective ends 2a, 3a of the mounting members 2, 3. Due to this structure, even if the band member 1 is fastened by the bolts 4 and nuts 5 until both ends 1a, 1b of the band member 1 or the respective ends 2a, 3a of the mounting members 2, 3 come into contact with each other, there is a physically discontinuous portion (hereinafter referred to as "missing portion 8") between both ends 1a, 1b or ends 2a, 3a of the band member 1.

Therefore, when the internal pressure exceeds the above-mentioned pressure, the stress is concentrated near the cutout 8, causing the cutout 8 to be pushed outward. As a result, as shown in Figure 10, the top plate 7 in the portion corresponding to the cutout 8 develops wrinkles caused by plastic deformation in a state where the top plate 7 bulges out like a mountain, that is, plastically deformed portion 9, which results in the seal provided by the packing being broken and a drop in pressure inside the drum.
As described above, the conventional open drum 50 cans had a problem in that it was difficult to improve the internal pressure resistance beyond the conventional value of about 100 kPa described above, or to improve the internal pressure resistance beyond the specified time at this conventional value.

Therefore, in order to further improve the above-mentioned internal pressure resistance performance, the applicant of the present application has already proposed and obtained a patent for a drum can top plate in which the top plate itself has been modified (Patent Document 1).

Patent No. 4825881

In the above-mentioned conventional open drum 50, the thickness (nominal thickness before processing) of the steel plate forming the can body 6 is usually 1.2 mm. The plate thickness of the can body 6 is related to the strength of the joint with the top plate 7 provided with the packing, and is one of the factors that directly affect the above-mentioned internal pressure resistance performance.
On the other hand, drum can users are requesting lighter drum cans and lower prices, and reducing the plate thickness of the can body 6 is an effective means of meeting this request, but as mentioned above, this raises concerns about the internal pressure resistance. Therefore, drum can manufacturers are being asked to come up with further ideas to satisfy both user demands and the above-mentioned performance improvements.

On the other hand, in conventional open drums, in addition to making improvements to the top plate of the drum as described above, there is also a method of making improvements to the bolt-type clamping ring as a method of improving the internal pressure resistance of the conventional open drums.

The present invention aims to provide a drum clamp that improves the internal pressure resistance of a drum when the drum body and top plate are fastened together by a bolt-type clamp, and a drum with the drum clamp attached.

In order to achieve the above object, the present invention is configured as follows.
That is, the drum clamp in the first aspect of the present invention is as follows:
A drum clamp is attached to an open drum having a detachable top plate from a can body and required to have internal pressure resistance, and fastens the can body and the top plate by a fastening action using an attached fastening member,
a band member having a discontinuous circular shape with one portion of the periphery cut out, the band member being attached to a peripheral portion of the top plate and a peripheral portion of the opening of the can body so as to sandwich the peripheral portions and fasten the peripheral portions together;
a first attachment member which holds the fastening member on the band member and is fixed to the band member from one end surface of one end of the band member along a circumferential direction of the band member, leaving an overlapping region in which the band member is exposed;
a second attachment member which cooperates with the first attachment member to hold the fastening member on the band member, protruding from the other end surface of the other end of the band member in the circumferential direction and fixed to the band member, and which covers the overlapping region of the band member by the fastening operation;
Equipped with
the second mounting member is fixed to the band member in a state in which a gap is formed between the one end surface of the band member and a tip surface of the second mounting member when the band member is attached to the peripheral portion of the top plate and the peripheral portion of the can body and the fastening member is not provided;
When the fastening member is provided and the first attachment member and the second attachment member are in contact with each other by the fastening operation, a gap between the one end surface and the other end surface of the band member is equal to or greater than zero and is less than the length of the overlapping region, and the first attachment member and the second attachment member are fixed to the band member,
A length of the second mounting member in the circumferential direction is greater than a length of the first mounting member,
The one end of the band member is formed in a tapered shape,
the band member, in an attached state, has a top plate side region in contact with the peripheral edge of the top plate and a body side region in contact with the peripheral edge of the opening, at least the top plate side region has deformation inducing portions at a plurality of desired locations spaced from the overlapping region in the circumferential direction of the band member, the deformation inducing portions being portions that intentionally induce deformation of the top plate caused by an increase in internal pressure of the sealed drum can at the desired locations on the top plate,
The band member has a U-shaped or V-shaped vertical cross section, and a vertex in the vertical cross section is formed at a joint between the top panel side region and the body side region,
The deformation inducing portion extends in a range from a starting point located on the opposite side of the apex in the top plate side region to approximately 2/3 of the top plate side region, or from the starting point through the apex to a part of the body side region .
It is characterized by:

A drum can in a second aspect of the present invention is an open drum can having a can body and a top plate that is detachable from the can body, and is required to have internal pressure resistance,
The drum can further includes a drum can fastening ring according to the first aspect, which fastens the can body and the top plate together by a fastening action using an attached fastening member.

According to the first embodiment of the drum clamp and the second embodiment of the open drum of the present invention, by providing a deformation inducing portion in the top plate side region of the band member, when internal pressure exceeds the above-mentioned conventional value, deformation is likely to occur in the portion of the top plate corresponding to the deformation inducing portion. Therefore, it is possible to avoid the stress concentrating in one place corresponding to the above-mentioned discontinuous portion as in the conventional case, and to disperse the stress. As a result, even if the top plate deforms due to internal pressure, the amount of deformation in each deformed portion is reduced, and it is possible to delay the deformation until it reaches an amount of deformation that causes a drop in internal pressure. Therefore, it is possible to improve the internal pressure resistance performance of the open drum compared to the conventional case.

Furthermore, with a drum clamp that has such an effect, it is possible to form the drum body using thinner steel plate than before. This improves the internal pressure resistance, and also makes it possible to reduce the weight and cost of the drum.

FIG. 2 is a plan view showing an example of a drum clamp in an embodiment of the present invention. FIG. 2 is a diagram showing part A shown in FIG. 1, and is a perspective view showing an example of a convex portion which is one form of a deformation inducing portion provided on the drum clamp ring of FIG. 1. 3 is a cross-sectional view of the band member at the deformation inducing portion shown in FIG. 2 . 3 is a cross-sectional view of a band member in an example of a modified example of the deformation inducing portion shown in FIG. 2 . 1. FIG. 4 is a perspective view showing an example of a convex portion with slits, which is another form of the deformation inducing portion shown in FIG. 2 is a perspective view showing an example of a slit only portion which is another form of the deformation inducing portion shown in FIG. 1 . FIG. FIG. 5B is a cross-sectional view of the band member at the location of the slit only portion shown in FIG. 5A. FIG. 5C is a perspective view showing an example of the shape of the slit shown in FIGS. 5A and 5B. FIG. 5C is a perspective view showing an example of the shape of the slit shown in FIGS. 5A and 5B. FIG. 2 is a cross-sectional view showing the state in which the drum can clamp ring shown in FIG. 1 is attached to the can body after the top plate is placed on the can body. FIG. 2 is a plan view showing an outline of a drum clamp in the applicant's Patent No. 5,409,023. FIG. 1 is a perspective view showing a conventional drum clamp. FIG. 9 is a diagram showing the state in which the drum can clamping ring shown in FIG. 8 is attached to a can body with a top plate covering the can body. 9 is a perspective view showing a state in which internal pressure acts on a drum to which the drum clamp ring shown in FIG. 8 is attached, causing a plastically deformed portion in the top plate. FIG.

The drum clamping ring according to an embodiment of the present invention and a drum to which the drum clamping ring is attached will be described below with reference to the drawings. In each drawing, the same or similar components are given the same reference numerals. In order to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art, detailed descriptions of already well-known matters and duplicate descriptions of substantially identical configurations may be omitted. In addition, the contents of the following description and the accompanying drawings are not intended to limit the subject matter described in the claims. In addition, in each drawing, the explanations may be exaggerated, and there are parts that do not match the actual dimensional relationships of the components.

First embodiment:
The drum can fastening ring 100 in this embodiment, which is a bolt type fastening ring as shown in Fig. 1, is attached to a conventional open drum can 50 (a steel open drum can specified in JIS Z 1600) in which the top plate 7 can be attached and detached from the can body 6 as described above, and fastens the can body 6 and the top plate 7 by fastening with bolts 4 and nuts 5, which correspond to an example of an accessory fastening member. The open drum can 50 fastened by the drum can fastening ring 100 is used as an open drum can withstand internal pressure by providing a packing 7b (Fig. 6) at the engagement part between the can body 6 and the top plate 7, and in this embodiment, an open drum can with a capacity of 200 liters is taken as an example. The packing 7b is placed in a groove in the curled part of the peripheral part 7a of the top plate 7 (also referred to as the peripheral part 7a of the top plate in Fig. 2), and can be made of, for example, natural rubber, a mixture of natural rubber and styrene butadiene rubber, neoprene rubber, or silicone rubber. As another example, in this embodiment, the diameter of the top plate 7 and the can body 6 is about 600 mm, the material is SPCC (cold rolled steel plate), the steel plate thickness of the top plate 7 is 1.2 mm, and the steel plate thickness of the can body 6 is 1.0 mm. Note that these steel plate thicknesses are all plate thickness dimensions (so-called nominal thicknesses) before processing into the can body 6, etc., but depending on the processing method, there may be cases where almost no reduction in thickness occurs, in which case the above thicknesses can also be interpreted as plate thickness dimensions after processing.

Of course, the drum can clamping ring 100 is not limited to 200-liter drums, and can be applied to any can container that requires internal pressure resistance. In addition, in this embodiment, bolts 4 and nuts 5 are used as fastening members, but this is not limited to this, and any member or mechanism that can tighten the drum can clamping ring 100 to fasten the can body 6 and the top plate 7 can be used.

The drum clamping ring 100 as described above basically comprises a band member 110, a first mounting member 2, and a second mounting member 3, and also has a bolt 4 and a nut 5 as fastening members. Therefore, the drum clamping ring 100 in this embodiment has the same configuration as a conventional clamping ring, except for the band member 110. In addition, the drum clamping ring 100 can also be called a bolt-type clamping ring.

As shown in FIG. 6, the band member 110 is a steel member having a generally U-shaped or V-shaped cross section and a discontinuous C-shaped circular shape in plan view with a notch 8 completely removed from one part of the periphery of the band member 110 to fasten the top plate peripheral portion 7a of the top plate 7 and the opening peripheral portion 6a of the can body 6. Since it has the notch 8, it can be fastened by the fastening action of the fastening member. In this embodiment, the band member 110 is made of SPHC (hot-rolled steel plate) as an example, and its thickness (nominal thickness) is 2.3 mm. Note that the "nominal thickness" also includes other thicknesses such as 1.6 mm and 2.0 mm, and the band member 110 can also be made using steel plates of these nominal thicknesses.

The first mounting member 2 and the second mounting member 3 are both members for attaching and holding the fastening members, the bolt 4 and the nut 5, to the band member 110. As already explained with reference to FIG. 8 etc., the first mounting member 2 is fixed to the band member 110 at one end 1a of the band member 110 in the notch 8, and the second mounting member 3 is fixed to the band member 110 at the other end 1b of the band member 110 in the notch 8.

The band member 110 will be described in more detail below.
The band member 110 has a top plate side region 111 in contact with the top plate peripheral portion 7a of the top plate 7 and a body side region 112 in contact with the opening peripheral portion 6a of the can body 6 in a substantially U-shaped or V-shaped cross section as shown in Fig. 6. At least the top plate side region 111 has a deformation inducing portion 120 at one or more desired locations in the circumferential direction 118 of the band member 110 as shown in Fig. 1. The deformation inducing portion 120 is a portion that intentionally induces deformation (swelling) of the top plate 7 caused by an increase in the internal pressure of the drum can 50 at a location corresponding to the desired location of the top plate 7. Fig. 1 shows a case where the deformation inducing portion 120 is disposed at two locations in the circumferential direction 118 of the band member 110, but the deformation inducing portion 120 may be disposed at a minimum of one location in the circumferential direction 118, and may be disposed at three or more locations up to a maximum of 15 locations.

The deformation inducing portion 120 will now be described in detail.
As one form of the deformation inducing portion 120, a convex portion 122 as shown in Fig. 2 can be considered. The convex portion 122 is a portion where the band member 110 is deformed toward the opposite top plate side 7c when the band member 110 is attached to the drum can 50, and is a portion where the top plate side region 111 of the band member 110 and the top plate peripheral portion 7a of the top plate 7 are not in contact with each other. By forming such a non-contact portion in the band member 110, deformation (swelling) is easily caused at the portion of the top plate 7 corresponding to the convex portion 122 when the internal pressure of the drum can 50 in a sealed state increases. Therefore, the concentration of stress caused by the increase in internal pressure in the top plate 7 can be suppressed, and the stress can be dispersed, thereby improving the internal pressure resistance of the drum can 50.

The protrusions 122 can be formed, for example, by pressing the band member 110, and microscopically, as shown in FIG. 2, have a trapezoidal shape along the circumferential direction 118 of the band member 110. However, the shape of the protrusions 122 depends on the method of forming the protrusions 122, and may be a square shape or the like, and the shape is not important.

The length L1 of the protrusion 122 in the circumferential direction 118 of the band member 110, i.e., the length at which the top plate side region 111 and the top plate peripheral portion 7a are not in contact, is set in a range of approximately 0.2% to 2.2% of the circumferential length of the top plate 7. As an example, the length L1 can be set to approximately 4 mm to approximately 40 mm. This range was set in relation to the method of forming the protrusion 122 and through the applicant's experiments, etc., and since there is no significant correlation between the length L1 and the intentional deformation action on the top plate 7 when the length L1 exceeds the above-mentioned 2.2%, the upper limit has been determined to be 2.2%.

In addition, in this embodiment, as shown in FIG. 3A, the convex portion 122 is formed over a range of approximately half or more than half of the tabletop side region 111 along the arc direction 117 in the longitudinal section of the band member 110. Specifically, the convex portion 122 is formed so as to exist in a range of approximately 30 degrees to approximately 80 degrees at an elevation angle α from a plane including the junction point of the tabletop side region 111 and the body side region 112, which is the apex 113 of the band member 110. In other words, the convex portion 122 corresponding to an example of the deformation inducing portion 120 in this embodiment extends in the tabletop side region 111 from a starting point 111a located on the opposite side of the apex 113 along the arc direction 117 to, for example, approximately 2/3 of the tabletop side region 111. Note that in FIG. 3A, the convex portion 122 is shown in a trapezoidal shape along the arc direction 117, but this shape is also due to the formation method as described above, and is not intended to limit the shape of the convex portion 122.

Furthermore, the convex portion 122 may be formed only in the top plate side region 111 as shown in FIG. 3A, but may extend beyond the apex 113 along the arc direction 117 of the band member 110 and further into the body side region 112 as shown in FIG. 3B. Also, in FIG. 3B, the convex portion 122 is shown extending partway into the body side region 112 in the arc direction 117, but it may be formed over the entire body side region 112, that is, over the entire top plate side region 111 and the body side region 112.

Next, as another embodiment of the deformation inducing portion 120, a convex portion 124 with a slit as shown in FIG. 4 is considered.
The slit-equipped convex portion 124 is obtained by adding a slit 125, i.e., a cut or incision, to the above-mentioned convex portion 122 so as to cut off a portion of the convex portion 122 in the circumferential direction 118. The slit 125 is formed along the diameter direction of the top plate 7 and along the arc direction 117, and is also formed in the center of the convex portion 122 in the circumferential direction 118. The length L2 of the slit 125 in the circumferential direction 118 is, for example, about 0.5 mm, but is not limited to this and can be set within the range up to the length L1 of the convex portion 122.

The location of the slit-equipped convex portion 124 is the same as that of the convex portion 122 described above. In this case, the range of the slit 125 is the same as or a part of the range of the convex portion 122 when the convex portion 122 exists only in the top plate side region 111, and is a range in which the slit 125 does not cut the band member 110 in both the circumferential direction 118 and the arc direction 117 when the convex portion 122 extends to both the top plate side region 111 and the body side region 112 along the arc direction 117 of the band member 110.

Such a slitted protrusion 124 has the same effect as the protrusion 122, that is, when the internal pressure of the drum 50 increases, it facilitates deformation at the location of the top plate 7 corresponding to the slitted protrusion 124. In addition, the presence of the slit 125 makes it easier to displace the protrusion 122 in the circumferential direction 118 compared to when only the protrusion 122 is provided, and therefore it is easier to intentionally deform the top plate 7. Therefore, the slitted protrusion 124 can further improve the internal pressure resistance performance.

5A and 5B, a further embodiment of the deformation inducing portion 120 may be such that the band member 110 is not provided with the protrusion 122 and only has a slit 125. For ease of explanation, this embodiment will be referred to as a slit only portion 126.
The arrangement range of the slits 125 in the slit only portion 126 in the arc direction 117 is also the same as in the case of the above-mentioned convex portion 122. However, similarly to the case of the slit-equipped convex portion 124, in a form in which the slits 125 extend along the arc direction 117 of the band member 110 to both the top plate side region 111 and the body side region 112, the slits 125 are within a range in which the slits 125 do not cut the band member 110 in both the circumferential direction 118 and the arc direction 117.
The length L2 of the slit 125 can be set within a range from the above-mentioned 0.5 mm to the above-mentioned length L1 (approximately 0.2% to 2.2%).

The action and effect of such a slit only portion 126 is similar to that of the slit convex portion 124, but compared to the slit convex portion 124, it also has the following effect.
That is, the slits 125 in the slit convex portion 124 and the slit only portion 126 can be formed by, for example, cutting or punching the band member 110. The slit only portion 126 is easier to process than the slit convex portion 124, and has the advantage of being able to reduce the cost of manufacturing the drum clamping ring 100.

In the above-described forming method, the slit 125 has a rectangular shape along the circumferential direction 118 of the band member 110, as shown in the example of the slit only portion 126 in Fig. 5C. However, the shape of the slit 125 depends on the forming method of the slit 125, and may be, for example, a U-shape as shown in Fig. 5D, and the shape is not limited.
In addition, in Figs. 5C and 5D, the slit 125 portion is shown in an exaggerated and enlarged manner in order to clearly show its shape.

The deformation inducing portions 120 described above are arranged in the circumferential direction 118 of the band member 110 as follows. Here, the deformation inducing portions 120 are at least one of the convex portions 122, the convex portions 124 with slits, and the slit only portions 126. In other words, when the deformation inducing portions 120 are arranged at multiple locations on the band member 110 in the circumferential direction 118, each deformation inducing portion 120 may be composed of only one of the three types, or may be composed of a combination of multiple different types of deformation inducing portions 120.

As already explained, the deformation inducer 120 is for intentionally deforming the top plate 7 at a location other than the missing portion 8, which is a discontinuous location in the band member 110 and a stress concentration location, in order to improve the internal pressure resistance performance of the drum 50, and therefore can be formed at at least one location in the circumferential direction 118 of the band member 110. The location corresponds to the opposing position of the missing portion 8, that is, a position 180 degrees in the circumferential direction 118 when the center position of the missing portion 8 in the circumferential direction 118 is set to 0 degrees. Here, since the convex portion 122, the convex portion with slits 124, and the slit only portion 126 all have a length (L1, etc.) in the circumferential direction 118 as described above, the center positions of the convex portion 122, the convex portion with slits 124, and the slit only portion 126 in the circumferential direction 118 become the reference positions, and the reference positions correspond to the opposing positions (180 degrees) (the same applies to the following cases).

Also, as shown in FIG. 1, the above-mentioned opposing position (180 degree position) can be disposed between them, and the deformation inducing portion 120 can be disposed at two locations on either side of the opposing position near the opposing position, i.e., at 135 degrees and 225 degrees in the circumferential direction 118, for example.

Furthermore, the deformation inducing portion 120 may be arranged at four positions in the circumferential direction 118: 45 degrees, 135 degrees, 225 degrees, and 315 degrees.

The deformation inducing portion 120 may be arranged symmetrically at intervals of 45 degrees or 22.5 degrees, or at a combination of these, in the circumferential direction 118. Here, symmetrical means symmetrical with respect to a diameter axis passing through the center point of the top plate 7 and the center position of the cutout portion 8 (the 0 degree position).
In this case, the maximum number of locations is 15, and in this case, the lugs can be arranged at 22.5 degrees, 45 degrees, 67.5 degrees, 90 degrees, 112.5 degrees, 135 degrees, 157.5 degrees, 180 degrees, 202.5 degrees, 225 degrees, 247.5 degrees, 270 degrees, 292.5 degrees, 315 degrees, and 337.5 degrees in the circumferential direction 118.
In addition, in the case of 13 locations, they can be placed at positions of 45 degrees, 67.5 degrees, 90 degrees, 112.5 degrees, 135 degrees, 157.5 degrees, 180 degrees, 202.5 degrees, 225 degrees, 247.5 degrees, 270 degrees, 292.5 degrees, and 315 degrees.
In the case of nine locations, the positions can be set at 45 degrees, 67.5 degrees, 90 degrees, 135 degrees, 180 degrees, 225 degrees, 270 degrees, 292.5 degrees, and 315 degrees.
In the case of seven locations, they can be arranged at positions of 45 degrees, 90 degrees, 135 degrees, 180 degrees, 225 degrees, 270 degrees, and 315 degrees.

According to the applicant's experiments, it has been confirmed that when four or more parts are arranged, the maximum pressure resistance does not improve significantly even if the number of parts is increased. However, this has the effect of reducing the variation in the internal pressure resistance at each arrangement position, resulting in more stable internal pressure resistance. The number of parts to be arranged can be determined in relation to the processing costs of the deformation inducing portion 120.

1, the top plate 7 is provided with a large plug (inlet) 7d and a small plug (ventilation hole) 7e, and it has been confirmed that the areas around the large plug 7d and the small plug 7e are locations where deformation of the top plate 7 is likely to occur when the internal pressure increases. Therefore, regarding the positional relationship between the large plug 7d and the small plug 7e and the cutout portion 8 of the band member 110 of the drum can fastening ring 100, the cutout portion 8 is basically located midway between the large plug 7d and the small plug 7e. In other words, it is preferable to orient the cutout portion 8 on a diameter axis perpendicular to the diameter axis connecting the large plug 7d and the small plug 7e.
However, since the drum clamp 100 is often attached by the customer, it cannot be positioned exactly at this location, and deviations occur.
Therefore, by increasing the number of deformation inducing portions 120 provided on the band member 110, the band member 110 can be made less susceptible to the influence of the above-mentioned misalignment.

In addition, in the case of the drum clamp 100 having the deformation inducing portion 120, processing of the band member 110 is easier than for the drum top plate, which has been designed to improve internal pressure resistance as in the applicant's previously mentioned patent, and this has the effect of reducing processing costs.

The operation of the drum clamp 100 having the deformation inducing portion 120 described above will now be described.
As already explained, the top plate 7 is placed on the opening peripheral portion 6a of the can body 6, and the band member 110 is attached so as to fasten the top plate peripheral portion 7a of the top plate 7 to the opening peripheral portion 6a. Then, the bolts 4 and nuts 5 are attached to the first mounting member 2 and the second mounting member 3, and the bolts 4 and nuts 5 are tightened, and the drum can 50 is sealed with the drum can tightening ring 100.

The applicant has confirmed the following results regarding the improvement in internal pressure resistance when a drum clamp 100 having a deformation inducing portion 120 is used for a drum 50 sealed in this manner.
The contact area between the packing 7b provided on the top plate 7 and the opening rim 6a of the can body 6 near the portion of the top plate 7 that deforms due to an increase in internal pressure was calculated, and the internal pressure resistance performance was evaluated using the calculation results. That is, for each of the deformation inducing portion 120, the convex portion 122, the convex portion 124 with a slit, and the slit only portion 126, the relationship between the contact area and internal pressure resistance was evaluated while changing the above-mentioned lengths L1 and L2.
As an example of the results, the improvement in internal pressure resistance performance compared to the conventional method was greatest in the drum tightening ring 100 having the deformation-inducing portion 120 consisting of the slit-equipped convex portion 124 and the slit-only portion 126, followed by the one having the convex portion 122 (especially one with L1 of 10 mm).

As described above, according to the drum tightening ring 100 of this embodiment, by providing a deformation inducing portion 120 in at least the top plate side region 111 of the band member 110, the internal pressure resistance of the open drum can be improved compared to the conventional case, even if the top plate 7 is deformed due to an increase in internal pressure of the drum.
Furthermore, by using the drum clamp 100, at least the can body 6 of the drum can be made from a thinner steel plate than before, for example, a steel plate having a thickness of 1.0 mm as in this embodiment, although of course a conventional steel plate having a thickness of 1.2 mm can be used. Furthermore, the can body 6 can be made from a steel plate having a thickness of less than 1.0 mm, for example, 0.9 mm, 0.8 mm, etc. By using a steel plate having a thickness of 1.0 mm or less, it is possible to reduce the weight and cost of the drum can while improving the internal pressure resistance.

Second embodiment:
As already explained, the above-mentioned deformation inducing portion 120 is a conventionally used clamping ring for drums that has been modified to form the deformation inducing portion 120. Meanwhile, the applicant has also proposed a clamping ring for drums as shown in Fig. 7 that incorporates a technique related to the above-mentioned cutout portion 8, also for the purpose of improving the internal pressure resistance of drums, and has already obtained a patent for this (Patent No. 5409023).
The drum clamp in Patent No. 5,409,023 (hereinafter referred to as the "patent clamp") has the following configuration.

That is, the drum can clamp ring 1000 (FIG. 7) is attached to an open drum can having a detachable top plate from a can body and required to have internal pressure resistance, and fastens the can body and the top plate by a fastening action using an attached fastening member,
a band member 1100 having a discontinuous circular shape with one portion cut out from the periphery, attached to the peripheral portion of the top plate and the peripheral portion of the opening of the can body so as to sandwich them together and fasten both of the peripheral portions;
a first attachment member 1210 which holds the fastening member on the band member and is fixed to the band member from one end face of one end portion 1120 of the band member along the circumferential direction of the band member, leaving an overlapping region 1140 in which the band member is exposed;
a second attachment member 1220 which cooperates with the first attachment member to hold the fastening member on the band member, protrudes from the other end surface of the other end portion 1130 of the band member in the circumferential direction and is fixed to the band member, and covers the overlapping region of the band member by the fastening operation;
Equipped with
the second mounting member is fixed to the band member in a state in which a gap is formed between the one end surface of the band member and a tip surface of the second mounting member when the band member is attached to the peripheral portion of the top plate and the peripheral portion of the can body and the fastening member is not provided;
When the fastening member is provided and the first attachment member and the second attachment member are in contact with each other by the fastening operation, a gap between the one end surface and the other end surface of the band member is equal to or greater than zero and is less than the length of the overlapping region, and the first attachment member and the second attachment member are fixed to the band member,
A length of the second mounting member in the circumferential direction is greater than a length of the first mounting member,
The one end of the band member is formed in a tapered shape.
This is a drum can fastening ring having the above configuration.

The above-mentioned deformation inducing portion 120 can also be applied to the above-mentioned patented clamp ring. The patented clamp ring itself can improve the internal pressure resistance performance, so by providing the deformation inducing portion 120, it is possible to improve the internal pressure resistance performance more effectively. In addition, as described above, the patented clamp ring provided with the deformation inducing portion 120 also makes it possible to use thinner steel plates than before, and it is expected that even for drums that comply with the above-mentioned UN standard, the can body can be formed with a steel plate with a thickness of less than 0.8 mm as described above. In this way, the patented clamp ring provided with the deformation inducing portion 120 can be expected to improve the internal pressure resistance performance more effectively, so it is expected that it will be possible to further reduce the weight and price of drums while improving the internal pressure resistance performance.

The present invention is applicable to a drum clamp that fastens the top plate to the body of an open drum, and to a drum to which the drum clamp is attached.

2, 3... mounting member, 4... bolt, 5... nut, 6... can body, 6a... opening periphery,
7 ... top plate, 7a ... top plate peripheral portion, 8 ... missing portion, 50 ... open drum can,
100: drum can fastening ring, 110: band member, 111: top plate side region,
112... fuselage side region, 120... deformation inducing portion, 122... convex portion,
124: convex portion with slit, 125: slit, 126: slit only portion.

Claims (9)

A drum clamp is attached to an open drum having a detachable top plate from a can body and required to have internal pressure resistance, and fastens the can body and the top plate by a fastening action using an attached fastening member,
a band member having a discontinuous circular shape with one portion of the periphery cut out, the band member being attached to a peripheral portion of the top plate and a peripheral portion of the opening of the can body so as to sandwich the peripheral portions and fasten the peripheral portions together;
a first attachment member which holds the fastening member on the band member and is fixed to the band member from one end surface of one end of the band member along a circumferential direction of the band member, leaving an overlapping region in which the band member is exposed;
a second attachment member which cooperates with the first attachment member to hold the fastening member on the band member, protruding from the other end surface of the other end of the band member in the circumferential direction and fixed to the band member, and which covers the overlapping region of the band member by the fastening operation;
Equipped with
the second mounting member is fixed to the band member in a state in which a gap is formed between the one end surface of the band member and a tip surface of the second mounting member when the band member is attached to the peripheral portion of the top plate and the peripheral portion of the can body and the fastening member is not provided;
When the fastening member is provided and the first attachment member and the second attachment member are in contact with each other by the fastening operation, a gap between the one end surface and the other end surface of the band member is equal to or greater than zero and is less than the length of the overlapping region, and the first attachment member and the second attachment member are fixed to the band member,
A length of the second mounting member in the circumferential direction is greater than a length of the first mounting member,
The one end of the band member is formed in a tapered shape,
The band member, in an attached state, has a top plate side region (111) in contact with the peripheral edge of the top plate and a body side region (112) in contact with the peripheral edge of the opening, and at least the top plate side region has deformation inducing portions (120) at a plurality of desired locations spaced apart from the overlapping region in the circumferential direction (118) of the band member, the deformation inducing portions being portions that intentionally induce deformation of the top plate caused by an increase in internal pressure of the sealed drum can at the desired locations of the top plate,
The band member has a U-shaped or V-shaped cross section, and forms a vertex (113) in the cross section at a joint between the top plate side region and the body side region,
The deformation inducing portion extends from a starting point (111a) located on the opposite side of the apex in the tabletop side region to approximately 2/3 of the tabletop side region, or from the starting point through the apex to a part of the body side region .
A tightening ring for a drum. A drum clamp is attached to an open drum having a detachable top plate from a can body and required to have internal pressure resistance, and fastens the can body and the top plate by a fastening action using an attached fastening member,
a band member having a discontinuous circular shape with one portion of the periphery cut out, the band member being attached to a peripheral portion of the top plate and a peripheral portion of the opening of the can body so as to sandwich the peripheral portions and fasten the peripheral portions together;
a first attachment member which holds the fastening member on the band member and is fixed to the band member from one end surface of one end of the band member along a circumferential direction of the band member, leaving an overlapping region in which the band member is exposed;
a second attachment member which cooperates with the first attachment member to hold the fastening member on the band member, protruding from the other end surface of the other end of the band member in the circumferential direction and fixed to the band member, and which covers the overlapping region of the band member by the fastening operation;
Equipped with
the second mounting member is fixed to the band member in a state in which a gap is formed between the one end surface of the band member and a tip surface of the second mounting member when the band member is attached to the peripheral portion of the top plate and the peripheral portion of the can body and the fastening member is not provided;
When the fastening member is provided and the first attachment member and the second attachment member are in contact with each other by the fastening operation, a gap between the one end surface and the other end surface of the band member is equal to or greater than zero and is less than the length of the overlapping region, and the first attachment member and the second attachment member are fixed to the band member,
A length of the second mounting member in the circumferential direction is greater than a length of the first mounting member,
The one end of the band member is formed in a tapered shape,
The band member, in an attached state, has a top plate side region (111) in contact with the peripheral edge of the top plate and a body side region (112) in contact with the peripheral edge of the opening, and at least the top plate side region has deformation inducing portions (120) at a plurality of desired locations spaced apart from the overlapping region in the circumferential direction (118) of the band member, the deformation inducing portions being portions that intentionally induce deformation of the top plate caused by an increase in internal pressure of the sealed drum can at the desired locations of the top plate,
The deformation inducing portion is a convex portion (122) of the band member in the attached state, which is a portion where the band member is deformed toward the side opposite the top plate (7c) and whereby the top plate side area and the peripheral portion of the top plate are not in contact with each other. 3. The drum clamp according to claim 2, wherein the length of the convex portion in the circumferential direction of the band member, where the top plate side region and the top plate peripheral portion are not in contact with each other, is in the range of 0.2% to 2.2 % of the top plate peripheral length. A drum clamp is attached to an open drum having a detachable top plate from a can body and required to have internal pressure resistance, and fastens the can body and the top plate by a fastening action using an attached fastening member,
a band member having a discontinuous circular shape with one portion of the periphery cut out, the band member being attached to a peripheral portion of the top plate and a peripheral portion of the opening of the can body so as to sandwich the peripheral portions and fasten the peripheral portions together;
a first attachment member which holds the fastening member on the band member and is fixed to the band member from one end surface of one end of the band member along a circumferential direction of the band member, leaving an overlapping region in which the band member is exposed;
a second attachment member which cooperates with the first attachment member to hold the fastening member on the band member, protruding from the other end surface of the other end of the band member in the circumferential direction and fixed to the band member, and which covers the overlapping region of the band member by the fastening operation;
Equipped with
the second mounting member is fixed to the band member in a state in which a gap is formed between the one end surface of the band member and a tip surface of the second mounting member when the band member is attached to the peripheral portion of the top plate and the peripheral portion of the can body and the fastening member is not provided;
When the fastening member is provided and the first attachment member and the second attachment member are in contact with each other by the fastening operation, a gap between the one end surface and the other end surface of the band member is equal to or greater than zero and is less than the length of the overlapping region, and the first attachment member and the second attachment member are fixed to the band member,
A length of the second mounting member in the circumferential direction is greater than a length of the first mounting member,
The one end of the band member is formed in a tapered shape,
The band member, in an attached state, has a top plate side region (111) in contact with the peripheral edge of the top plate and a body side region (112) in contact with the peripheral edge of the opening, and at least the top plate side region has deformation inducing portions (120) at a plurality of desired locations spaced apart from the overlapping region in the circumferential direction (118) of the band member, the deformation inducing portions being portions that intentionally induce deformation of the top plate caused by an increase in internal pressure of the sealed drum can at the desired locations of the top plate,
The deformation inducing portion is a slit (125) formed along the diameter direction of the top plate only in the top plate side region or from the top plate side region to a portion of the body side region. The tightening ring for a drum according to claim 1 , wherein the deformation inducing portions are present on both sides of the overlapping region in a circumferential direction of the band member. The drum clamp according to any one of claims 1 to 4 , wherein the deformation inducing portions are arranged in a circumferential direction of the band member at intervals of 45 degrees, 22.5 degrees, or a combination thereof, with the overlapping region at 0 degrees. The drum clamp according to claim 6 , wherein the deformation inducing portions are arranged at 2 to 15 locations in a circumferential direction of the band member. 8. The drum clamp according to claim 1, wherein the can body has a plate thickness in the range between 0.8 mm and 1.0 mm. A can body (6),
and a top plate (7) that is detachable from the can body, and the open drum can is required to have internal pressure resistance,
9. An open drum further comprising a drum clamp (100) according to any one of claims 1 to 8 , which fastens the can body and the top plate together by a fastening action using an attached fastening member.

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