JP2001341101A - Electric circular saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reasonably structured electric circular saw wherein one guide part can be used for not only both left and right sides of saw blade but also in either of the case where a material to be cut escapes to a guide part side in cutting operation and the case where the material to be cut does not escape to the guide part side, the saw blade can be smoothly and surely guided. SOLUTION: In the electric circular saw 101 having a base 110 abutting against a material to be cut W, a circular saw main body 110 rotatably supporting the saw blade by being provided on a base 110, and a guide part 130 guiding an advance of the saw blade by being slid along a side face of the material to be cut W when the material to be cut W is cut by advancing the saw blade, a side face on the base 110 side of the guide part 130 constitutes guide faces 131a and 132a, and the part 132a of the guide faces is made movable in a direction of approaching or being separated from the base 110.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric circular saw, and more particularly to a technique for forming an electric circular saw having a guide portion for guiding a cutting operation by a saw blade using a side surface of a material to be cut.

[0002]

2. Description of the Related Art In an electric circular saw, when a material to be cut (particularly wood) is cut by a saw blade, a guide portion arranged in parallel with the saw blade is slid along a side surface of the material to be cut. A technique for guiding a cutting operation by a blade is known. Such a guide portion is generally called a parallel ruler or a lip fence. As a problem relating to the guide portion sliding along the side surface of the material to be cut as described above, the material to be cut cut by the saw blade tries to escape in a direction orthogonal to the cutting direction of the material to be cut by the saw blade. Therefore, there is a problem that the cut material presses the guide portion outward, and smooth sliding of the guide portion is hindered. As a first prior art for addressing this problem, Japanese Unexamined Patent Publication No. 6-312402 concerning a portable electric circular saw has a relief surface formed on the guide surface of the guide portion on the rear side in the traveling direction of the saw blade. Techniques are disclosed. A similar technique is disclosed in Japanese Utility Model Application Laid-Open No. 49-126993 relating to a circular sawing machine. However, in these techniques, when the mounting surface of the guide portion with respect to the circular saw is reversed, for example, by replacing the guide portion mounted on the right side of the circular saw with the left side, the material to be cut actually tries to escape. Since the position of the flank and the position of the flank face are reversed in the cutting direction, there is a problem that the guide portion cannot be of the left / right type. For this reason, a second prior art is disclosed in
In Japanese Patent No. 224701, in a portable electric circular saw, a guide portion is formed by a guide base and a guide surface component shorter than the guide base, and the mounting position of the guide surface component on the guide base can be changed. Techniques are disclosed. In addition, Japanese Utility Model Laid-open No. 4-76 for circular sawing machines
Japanese Patent Publication No. 405 also discloses a technique for attaching a guide surface constituent member shorter than the guide base to the guide base. According to these techniques, since the guide surface constituting member can be positioned only on a part of the guide base, even if the cut material escapes outward, smooth sliding of the guide portion can be ensured. Since the mounting position of the guide surface constituting member with respect to the guide base can be appropriately changed, the guide portion can be of a left / right type.

[0003]

In the case where the cut material does not escape due to the material and the thickness of the material to be cut, the guide portion is formed over the entire material to be cut. It is desirable to perform stable guide by sliding contact with the surface. However, in the second prior art, the guide surface is not formed over the entire guide plate, and the overall contact state cannot be ensured.

[0004] The object of the present invention is not only to be able to use one guide part on both the left and right sides of the saw blade, but also if the material to be cut escapes to the guide part side during the cutting operation and if the material to be cut is guided by the guide part. An object of the present invention is to provide an electric circular saw having a reasonable structure capable of smoothly and reliably guiding a saw blade in any case where the electric circular saw does not escape to a part side.

[0005]

Means for Solving the Problems The above-mentioned problems are solved by the invention described in each claim. The electric circular saw of the present invention
As described in claim 1, the guide portion arranged in parallel with the saw blade forms a guide surface on which the side surface on the saw blade side of the guide portion comes into contact with and slides on the side surface of the material to be cut. And at least part of the guide surface is close to the saw blade.
It is movable in the separating direction. By making a part of the guide surface movable, the guide surface of the guide portion is entirely in contact with the side surface of the material to be cut and slid, and only a part of the guide surface is cut. It is switchable between a partial contact state in which the member slides in contact with the side surface of the material. The electric circular saw in the present invention includes both a portable circular saw and a circular saw machine.

To make a part of the guide surface movable, for example,
It is preferable that the guide portion is composed of a plurality of constituent members, and a part of the plurality of constituent members is relatively movable with respect to other constituent members in a direction orthogonal to the cutting direction of the saw blade. Corresponding to the invention described in (1). Thereby, the guide portion can be switched between the full contact state and the partial contact state. Further, a configuration may be adopted in which a part of the guide member can be switched between the general contact state and the partial contact state by rotating a part of the guide member relatively to other constituent members. 3)).
As for the mutual rotation of the components, a configuration in which some components rotate toward or away from the saw blade, or some components rotate around the long axis with respect to other components. Any of these may be used.

[0007] With this configuration, when the cut material is to escape outward from the saw blade side to the guide portion side when cutting the material to be cut, it is possible to cope with such escape. Thus, a part of the guide surface is shifted in a direction away from the saw blade. Specifically, the guide surface on the front side of cutting by the saw blade is slid in contact with the side surface of the material to be cut, and the guide surface on the rear side of cutting by the saw blade is more outward than the side surface of the material to be cut. It is preferable that the state be shifted. As a result, the material to be escaped to the outside does not press the guide surface outward on the rear side of the cutting by the saw blade, and a smooth sliding operation of the guide portion is secured.

When the material to be cut does not escape outward (for example, when cutting a thin plate), it is preferable that the guide surface of the guide portion is flush (equivalent surface). In other words, it is preferable that the “entire contact state” is such that the guide surface of the guide portion is entirely in contact with the side surface of the workpiece and slides. Thereby, a stable guide at the time of the cutting operation can be provided.

In the present invention, since a part of the guide surface is movable in a direction approaching or separating from the saw blade, it is possible to appropriately select which part of the guide surface is close to or away from the saw blade side. By doing so, both the guide portion mounted on the right side of the saw blade and the guide portion mounted on the left side of the saw blade can be shared.

According to a fourth aspect of the present invention, the guide portion of the portable electric circular saw is formed by a plurality of constituent members into a long shape having a major axis in a traveling direction of the saw blade. It is preferable that the guide portion is attached to a guide bar protruding from the base so as to be arranged in parallel, and furthermore, a guide surface is formed so that the side surface of the guide portion on the base side slides in contact with the side surface of the cut material. Furthermore, the components of the guide portion are configured to be releasably engaged by the engagement means, and when the engagement means is released, one of the components is moved in the direction of the saw blade with respect to the other component. It is preferable to adopt a configuration that relatively moves in a direction perpendicular to the direction. With such a configuration, the entire contact state in which the guide surface entirely contacts and slides on the side surface of the material to be cut, and a part of the guide surface in the traveling direction side of the saw blade is Can be switched between a partial contact state slid and in contact with the side surface of the.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electric circular saw according to an embodiment of the present invention will be described in detail with reference to the drawings. In this embodiment, a portable electric circular saw is described as an example. As shown in FIGS. 1 and 2, a circular saw 101 according to the present embodiment generally includes a base 110 mounted on a material to be cut, and a circular saw main body 120 provided on the base 110. And a guide portion 130 that slides along the side surface of the material to be cut. In FIG. 2, the relationship between the workpiece W and the guide portion 130 indicated by a two-dot chain line is shown.
The circular saw body 120 includes a saw blade 121, a blade cover 122 that covers the saw blade 121, a motor housing 123 that houses a motor for rotating the saw blade 121,
A handle 125 for performing the cutting operation by moving the circular saw 101 forward.

The guide section 130 includes a pair of guide bars 13.
It is attached to the base 110 via 3,133.
Each guide bar 133 is at right angles to the traveling direction X of the circular saw 101 (that is, the traveling direction of the saw blade 121).
It is inserted into a fitting hole 113 formed on the base 110 and is releasably fixed to the base 110 by a holding screw 111. At one end (right end in FIG. 2) of the guide bar 133, the guide portion 13 is attached via a mounting screw 135.
0 is attached.

The guide portion 130 is arranged in parallel with the traveling direction X of the circular saw 101 (the traveling direction of the saw blade 121), and is formed longer than the base 110 in the traveling direction X of the circular saw 101. It has a first guide member 131 and a second guide member 132 engaged via means 137. The side surface on the base 110 side (the left side surface of the guide portion 130 in FIG. 2) of the first and second guide member members 131 and 132 is used to cut the workpiece W when cutting the workpiece W. Guide surfaces 131a and 132a for guiding the cutting operation by sliding along the side surface (the right side surface of the workpiece W in FIG. 2) are formed. Base 1
The gap D between the guide bar 10 and the guide unit 130 can be appropriately increased or decreased by adjusting the fixing position of the guide bar by the guide bar holding screw 111. Note that the first and second
Mounting members 15 and 132 are attached to the guide members 131 and 132.
3, barrier portions 151 and 152 are attached.
The significance of the barrier will be described later.

First and second guide member 13
1 and 132 release the engagement of the engagement means 137, and thereby a direction orthogonal to the traveling direction X of the circular saw 101 (FIG. 2).
In the left and right directions). Since the guide members 131 and 132 are fixed to the guide bar 133 by mounting screws 135, when the guide members 131 and 132 are relatively moved, the engagement of the engaging means 137 is released. Release the fixation of the guide bar 133 by the guide bar holding screw 111,
This is performed by appropriately moving the guide bar 133 in the left-right direction in FIG. In FIG. 2, the first guide member 131
Of the second guide member 1 against the guide surface 131a
32 is in a state where it is shifted in a direction away from the base 110. That is, the guide portion 13
0, the guide surface 13 on the front side in the traveling direction X of the circular saw 101
1a is in sliding contact with the (right) side surface of the workpiece W,
The guide surface 132a on the rear side in the traveling direction X is shifted in a direction away from the base 110, and a gap C is formed between the guide surface 132a and the workpiece W.

FIGS. 3A to 3C show the detailed structure of the first guide member 131 and the second guide member 132 constituting the guide part 130. FIG. FIG.
FIG. 3A shows a state where the second guide member 132 is relatively shifted rightward in the drawing with respect to the first guide member 131, and FIG. 3B shows the first guide. This shows a state in which the component member 131 and the second guide member 132 are placed at the same position, and the guide surface 131a and the guide surface 132a are flush. Note that FIGS. 3A and 3B
In, the traveling direction of the circular saw is indicated by the symbol X. FIG.
(C) shows a state in which the guide portion 130 is viewed from the side, in which the engagement convex portion 141 is fitted into the engagement concave portion 142 and the first
3 shows a state in which the guide member 131 and the second guide member 132 are connected. A large number of cavities H are formed inside the first guide member 131 and the second guide member to reduce the weight and ensure rigidity.

The details of the engaging means 137 for releasably engaging the first and second guide member members 131 and 132 in the guide part 130 are shown in FIGS.
(A) and (B). As shown in FIG. 4A, the engagement means 137 has an engagement knob 138 and an engagement claw 139. The engagement knob 138 is urged by the spring 138b in the direction of the engagement claw portion 139 (to the left in the drawing).
38a and 139a are engaged with each other, so that the first and second guide member members 131 and 132 are engaged with each other.

First and second guide member 13
When the engagement of the engagement knob 138 is released, the engagement knob 138 is separated from the engagement claw 139 while facing the urging force of the spring 138b (the rightward arrow in the figure stamped on the engagement knob 138). 138a, 139).
Release the engagement with a. At the same time, one guide member is shifted relative to the other guide member. In this embodiment, FIG. 4B shows a state in which the second guide member 132 is shifted with respect to the first guide member 131. FIG.
In (B), after the second guide member 132 is shifted, the engagement knob 138 is again moved toward the engagement claw 139 by the urging force of the spring 138b, and the claws 138a and 139 are moved.
The state where a is engaged is shown.

FIGS. 5A and 5B show a detailed longitudinal sectional structure of the first and second guide member 131, 132 of the guide 130. FIG. The engagement knob 138 is connected to the retaining member 13.
8c and the screw 138d are attached to the tip of the second guide member 132, and the engaging claw 139 is attached to the tip of the first guide member 131 via the screw 139b. FIG. 5A shows a state in which the engagement knob 138 and the engagement claw 139 are engaged by the urging force of the spring 138b, and FIG. FIG. 5 shows a state in which it is moved in a direction away from the right side (rightward direction in the figure) and disengaged.

FIGS. 6A and 6B show the bottom structure of the guide section 130, and FIG. 6C shows the structure of the guide surfaces 131a and 132a in the guide section 130. FIG. FIG. 6 (A)
As shown in (B), the first and second guide portion constituting members 131 and 132 are relatively movable and are prevented from falling off via a retaining screw 143 and a slide groove 145.

When the work to be cut is to be cut using the circular saw 101, it is necessary to take measures to prevent the guide portion from sliding due to the cut cut material escaping outward. In this case, in the circular saw 101 configured as described above, the first and second guide member 131,
This can be dealt with by shifting 132 relatively in a direction perpendicular to the saw blade. That is, as shown in FIG. 2, the second guide member 132 is shifted more outward than the first guide member 131 in a direction perpendicular to the circular saw 101 (a direction perpendicular to the saw blade).
Accordingly, when the circular saw 101 is advanced in the traveling direction X to perform a cutting operation, the cut material escapes outward (in a direction from the base 110 to the guide portion 130) on the rear side in the traveling direction X. The second guide member 132 that constitutes the rear guide surface of the guide 130 may be used.
Since the gap C is formed between the workpiece and the workpiece W, the guide surface 132a is not strongly pressed by the workpiece that is going to escape outward. Therefore, even if the material to be cut tries to escape to the outside during the cutting operation, the guide portion 1
Smooth sliding of 30 can be ensured.

When the material to be cut does not escape outward during the cutting operation, the guide portion 130 is in the state shown in FIG. 3B, that is, the first and second guide surfaces 131a and 132a are flush. Keep it in a state. As a result, the flush guide surfaces 131a and 132a are integrally brought into sliding contact with the side surfaces of the material to be cut, so that stable cutting work can be guided.

During the cutting operation, the mounting surface of the guide portion with respect to the base may be switched left and right depending on the cutting position of the material to be cut. For example, as shown in FIG.
The guide 130 mounted on the right side of the base 10 is mounted on the left side of the base 110 as shown in FIG.
This is a case in which it is slid in contact with the left side surface. The switching of the mounting surface is performed by switching the insertion direction of the guide bar 133 to the fitting portion 113 while releasing the pressing of the holding screw 111. In this case, with respect to the traveling direction X of the circular saw 101, the front-back relationship between the first guide member 131 and the second guide member 132 is switched. Accordingly, in the state shown in FIG. 7, the first guide member 131 located on the rear side in the traveling direction X is
By shifting in the direction away from 0 (to the left in FIG. 7), measures to prevent the sliding of the guide portion 130 are taken. Thus, the circular saw 101 according to the present embodiment is
Therefore, even when the guide section 130 is mounted on either the left or right surface of the base 110, the slide inhibition of the guide section 130 can be effectively prevented, and the guide section 130 can be configured for both left and right. It is. In the present embodiment,
The guide portion 130 is connected to the base 11 via the guide bar 133.
Although the guide portion 130 is attached to the circular saw main body 120, the guide portion 130 may be attached to the circular saw main body 120.

Next, the details of the barrier portions 151 and 152 shown in FIG. 2 will be described. The barrier portions 151 and 1 in FIG.
Reference numeral 52 is attached via mounting screws 153 so as to be in contact with the guide surfaces 131a, 132a on the upper surfaces of the first and second guide member 131, 132. 8 and 9 show the relationship among the barrier portions 151 and 152, the guide member 131, 132, and the guide bar 133. FIG. FIG. 8 shows a guide member 131,1.
This shows a configuration in which a gap S formed between the second guide 32 and the guide bar 133 is closed by barriers 151 and 152. On the other hand, FIG. 9 shows a configuration in which the gap S is not closed. 8 and 9
Are the barrier portions 151, 1 by the mounting screws 153.
It can be selected as appropriate by loosening the tightening of 52 and changing the arrangement position of the barrier portions 151 and 152. FIG. 10 shows a structure for loosening the mounting screw 153.

Since the relationship between the barriers 151 and 152 and the gap S can be switched, the following usage modes are possible. First, when the cutting width in the cutting operation is small, that is, the distance from the saw blade 121 to the side surface (guide surface) of the material to be cut is short, and the guide portion 130 is close to the base 110 and interferes with the position. When the cutting operation is performed, the barrier portions 151 and 152 are retracted so that the upper end edge of the guide portion 130 can sink under the base 110 to be in a state shown in FIG. On the other hand, when cutting a thin plate or the like, for example, the cut thin plate may warp upward and enter the gap S between the guide bar 133 and the guide portion 130 due to vibration or the like. In the case where the material to be cut is a thin plate, the effective area of the guide surface that slides on the side surface of the thin plate is reduced, so that the edge of the thin plate may enter the gap S due to vibration during operation or the like. In any case, the thin plate may get caught in the gap S and hinder the cutting operation. Accordingly, in order to prevent the edge of the thin plate from entering the gap S, the configuration is such that the barriers 151 and 152 block the gap S (the configuration in FIG. 8). FIG. 3A corresponds to FIG. 8 and shifts the second guide member 132 outward with respect to the first guide member 131 and moves the barriers 151 and 152 to the guide surfaces 131a and 132a. It shows the state arrange | positioned at the side. FIG. 3B shows that the second guide member 132 is disposed at the same position as the first guide member 131, and the barriers 151 and 152 are connected to the guide surface via the mounting screw 153 and the groove 153a. 131a, 132a
And shows a state where it is retracted to the opposite side.

(Other Modifications) In the above-described embodiment, the guide portion is divided into two constituent members, each of the constituent members is formed with a guide surface, and each of the constituent members can be relatively shifted. . In this regard, a configuration is possible in which the guide portion itself is integrally formed, the guide surface is formed of a plurality of surface members, and each surface member is relatively movable in a direction orthogonal to the saw blade. Thereby, when the material to be cut is to escape outward, the surface member located on the rear side in the traveling direction of the saw blade is shifted outward to cope with the problem, and the material to be cut is to escape to the outside. If not, the respective surface members can be placed at the same position (in the same plane) and slidably contacted with the side surface of the material to be cut as a whole to perform stable guiding.

Further, a part of the plurality of constituent members constituting the guide portion may be configured to be rotatable outward with respect to the other constituent members. In this case, when the material to be cut is going to escape outward, a countermeasure is taken by rotating the component member located rearward in the traveling direction of the saw blade outwardly to escape the material to be cut. Also, a part of the plurality of constituent members constituting the guide portion is configured to be rotatable around the long axis of the other constituent members, and guides before and after rotation in a direction perpendicular to the saw blade. It is also possible to configure so that the positions of the surfaces are different.

In this embodiment, a portable electric circular saw has been described as an example. However, the present invention can be further configured as a circular saw. FIGS. 11 and 12 show a configuration of a circular saw 201 as a modification. The circular saw 201
A base 210 provided on the base 211, a motor unit 223 disposed in the base 211, and connected to the motor unit 223 to rotate and partially project from the base 210 to cut the material to be cut. Saw blade 221 and mounting part 2
Guide portion 230 fixed to base 210 via 33
Having. As shown in FIG. 11, the cut material W made of wood is fed upward in the drawing while being guided by sliding the side surface thereof to the guide portion 230. The traveling direction of the material to be cut W is indicated by reference numeral Y in the figure. In the case of the above-mentioned portable circular saw, the cutting operation is performed while the saw blade advances on the fixed workpiece, whereas in the case of the circular sawing machine, the fixed saw blade is used. On the other hand, the material to be cut advances and a cutting operation is performed.
In any case, the phenomenon in which the cut material escapes outward to the guide portion occurs on the rear side of the cutting work site by the saw blade. The guide portion 230 includes a first guide member 231 and a second guide member 232.
Having. The workpiece W shown in FIG. 11 is cut by the saw blade 221 while being fed upward (Y direction) in the figure. Therefore, it is necessary to cope with the case where the cut material W1 at the upper part of the cut material W, that is, the cut rear side escapes to the guide portion 230 side. In other words, it is necessary to cope with the case where the cut workpiece W1 tries to escape outward in the direction perpendicular to the direction Y, that is, from the saw blade 221 to the guide portion 230 on the cutting rear side. For this reason,
As shown in FIG. 11, the second guide member 232
Are shifted outward (leftward in the figure) relative to the first guide member 231. This allows
It is avoided that the material to be cut W1 trying to escape outward strongly presses the guide portion 230, and a smooth sliding operation between the guide portion 230 and the material to be cut W is ensured.
In addition, about the structure for engaging the 1st guide part structural member 231 and the 2nd guide part structural member 232,
Since the configuration is the same as that of the portable circular saw described above, a detailed description is omitted for convenience.

In the circular saw 201, the case where the sliding surface between the workpiece W and the guide portion 230 is changed from left to right is shown by a two-dot chain line in FIG. In this modification, the attachment of the guide portion 230 to the base 210 by the attachment portion 233 is released, and the guide portion 230 is shifted in parallel to the right in the drawing. Then, it is fixed to the position shown by the two-dot chain line via the mounting portion 233. In this case, each guide surface 23 of the first and second guide portion constituting members 231 and 232 is used.
Since the constituent surfaces of 1a and 232a are reversed left and right, the second guide member 232 is shifted rightward in the figure with respect to the first guide member 231. by this,
While being guided through the right side surface of the cut material W, smooth sliding is ensured when the cut cut material W2 tries to escape outward (to the right in the drawing). .

[0029]

According to the present invention, one of the right and left sides of the saw blade can be used as a single guide portion. In addition, when the material to be cut escapes to the guide portion side during the cutting operation, Therefore, an electric circular saw having a reasonable structure capable of smoothly and reliably guiding the saw blade in any case where the electric circular saw does not escape to the guide portion side is provided.

[Brief description of the drawings]

FIG. 1 is a front view showing the entire structure of a circular saw according to an embodiment.

FIG. 2 is a plan view showing the entire structure of the circular saw according to the embodiment.

FIG. 3 is a diagram showing a structure of a guide unit.

FIG. 4 is a view showing a structure of an engagement means in a guide portion.

FIG. 5 is a cross-sectional view showing a structure of an engagement means in a guide portion.

FIG. 6 is a view showing a structure of a guide unit.

FIG. 7 is a plan view showing a state where a guide portion is mounted on the left side of the circular saw.

FIG. 8 is a diagram illustrating a relationship between a guide portion, a guide bar, and a barrier portion.

FIG. 9 is a view showing the relationship between a guide portion, a guide bar, and a barrier portion.

FIG. 10 is a diagram showing the structure of a barrier section in detail.

FIG. 11 is a plan view showing the structure of a circular saw according to a modification.

FIG. 12 is a front view showing the structure of a circular saw according to a modification.

[Explanation of symbols]

 Reference Signs List 101 circular saw 110 base 120 circular saw main body 121 saw blade 123 motor housing 125 handle 130 guide part 131 first guide part constituent member 131a first guide surface 132 second guide part constituent member 132a second guide surface 133 Guide bar 137 Engagement means 151 Barrier

Claims (4)

[Claims] 1. A cutting method for cutting a workpiece by relatively advancing the saw blade with respect to the workpiece, a base abutting on the workpiece, a saw blade rotatably provided on the base, and a saw blade. A guide portion that guides the cutting operation of the saw blade by being slid along the side surface of the material to be cut, wherein the guide portion is arranged in parallel with the saw blade. A side surface on the saw blade side of the guide portion that forms a guide surface that is slid in contact with a side surface of the material to be cut, and a direction in which at least a part of the guide surface approaches or separates from the saw blade. The guide surface is entirely in contact with and slides in contact with the side surface of the material to be cut, and a part of the guide surface is in contact with the side surface of the material to be cut. Can be switched between the partial contact state and the sliding And an electric circular saw. 2. The electric circular saw according to claim 1, wherein the guide portion is composed of a plurality of constituent members, and a part of the plurality of constituent members is in a cutting direction of the saw blade with respect to another constituent member. An electric circular saw characterized by being relatively movable in a direction perpendicular to the direction of rotation, whereby the guide portion can be switched between the full contact state and the partial contact state. 3. The electric circular saw according to claim 1, wherein the guide portion includes a plurality of constituent members, and a part of the plurality of constituent members is rotatable relative to other constituent members. The electric circular saw, wherein the guide portion is switchable between the full contact state and the partial contact state. 4. A base mounted on a material to be cut, a circular saw main body provided on the base and rotatably supporting a saw blade, and a saw blade being advanced to move the material to be cut. A portable electric circular saw having a guide portion that guides the advance of the saw blade by being slid along the side surface of the material to be cut when cutting, wherein the guide portion has a plurality of configurations. A guide bar protruding from the base so as to be arranged in parallel with the saw blade, the guide bar being formed in a long shape having a major axis in a traveling direction of the saw blade, The side surface of the side constitutes a guide surface that is slid in contact with the side surface of the material to be cut, and the constituent members are releasably engaged by engaging means, and the engaging means is released. In the meantime, one of the constituent members moves the saw blade relative to the other constituent member. Relative movement in the direction perpendicular to the cutting surface, whereby the guide surface entirely slides in contact with the side surface of the workpiece, and a part of the saw blade in the traveling direction side An electric circular saw characterized in that the guide surface can be switched between a partial contact state in which the guide surface is slid in contact with a side surface of the material to be cut.